,etteritiP 




Class _n^ 
Book. Lj5 ^ 






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COBTRIGUT DEPOSn^ 



NOTES ON 

Technical Sketching and Free Hand Lettering 



FOR ENGINEERING STUDENTS 



BY 

ALTON L. SMITH, M. S. 
Professor of Machine Design 
Worcester Polytechnic Institute 



PtTBLISHED BT THE AUTHOR 
WOBCESTER, MASS. 

1912 






Copyi-ight, 1912 

By Alton L. Smith, M. S. 

Worcester, Mass. 



HfJ-^ 



gCI.A3a0631 



Printed by 

The Davis Press 

Worcester, Mass, 



PREFACE 

The modern engineer must know how to make drawings in order to know how to read them. How- 
ever, very Uttle of his timeis spent at the drafting board. His drawings consist mainly of sketches show- 
ing his ideas in more or less detail and which are turned over to subordinates to be worked out and put in 
the conventional form. In the solution of his construction problems, he is obliged to keep in mind all 
three dimensions of materials and a preliminary sketch stands in the place of a model which he can work 
over and examine in order to clarify and fix his ideas. Such sketches must often be made in great profu- 
sion and dexterity with the pencil is frequently an inspiration to the brain. 

One of the primary functions of a course in drawing is to cultivate and extend the faculty of men- 
tally picturing unseen forms. In acquiring this faculty, the draftsman must be able to express his ideas 
quickly and accurately through the medium of drawings. He must also learn to. read correctly the ideas 
of other engineers as expressed in drawings. 

The actual construction of an object from the drawing representing it is a crucial test of ability to 
read that drawing. There are many disadvantages of such a test applied for that purpose alone and it is 
beUeved that the translation from a projection drawing of the object to an axometric or isometric represen- 
tation meets all the requirements of the case with far less expenditure of time. The reverse process also 
gives a most valuable training and the author beheves, after long experience in this work, that the methods 
herein presented secure the best results with the least effort. 

Though devoted primarily to the teaching of drawing, the illustrations and problems have been 
selected so as to give the student famiharity with a wide range of modern manufacturing and engineering 
practice. A considerable amount of matter has been added for this third edition and the author wishes 
to thank the many friends who have provided material or given suggestions. 

Worcester, July 20, 1912. A. L. S. 



CONTENTS 

Chapter I. page 

Description of Methods of Representation 7 

Chapter II. 
Shop Drawings and Blue Printing ' 16 

Chapter III. 
Miscellaneous Details of Construction 34 

Chapter IV. 
Toothed Gearing 47 

Chapter V. 
Structural Drawing 57 

Chapter VI. 
General Suggestions on Technical Sketching 70 

Chapter VII. 
Sketches for Shop Drawings and Electrical Symbols .... 76 

Chapter VIII. 
Geometric Perspective and Artists' Perspective 85 



Chapter IX. page 

Axometric Sketching 92 

Chapter X. 

Isometric Drawings and Cabiaet Projections 106 

Chapter XI. 

Comparison of ]Methods of Representation 109 

Chapter XII. 

Shade Lines and Line Shading Ill 

Chapter XIII. 

Free Hand Lettering 116 

Tables • 134 

Index I55 



TABLES 

Table 1 . — Decimal Equivalents of Common Fractions. Whitney or Woodruff Keys. page 

U. S. Standard Bolts and Nuts 134 

Table 2. — Hexagon and Square Head Cap Screws. Set Screws 135 

Table 3. — Fillister Head Cap Screws. Button and Countersunk Head Cap Screws .... 136 

Table 4. — Collar Screws. Studs. A. L. A. M. Standard. Bolts and Nuts 137 

Table 5. — Machine Screws, A. S. M. E. Standard Machine and Wood Screw Gage. 

Twist DriU and Steel Wire Gage 138 

Table 6. — Heads of Gib Head Keys. Lengths of Plain and Gib Head Keys 139 

Table 1.- — Square Feather Keys. Straight Flat Keys. Machine Knobs. Wing Nuts . . . 140 

Table 8. — Machine Hand Wheels 141 

Table 9. — Ball Machine Handles. Standard Punched Washers 142 

Table 10.— Cast Washers. Sprmg Cotters. T Slots. Eye Bolts . . .' 143 

Table 11. — Properties of Wrought Iron Pipe 144 

Table 12. — Fittings for Pipe ^failings . 145 

Table 13.— Standard Tapers 146 

Table 14. — Gage Lines. Rivet Spacing. Rivet Dimensions. Clearances 147 

Table 15. — Jaw Clutch Couphngs 1. Jaw Clutch Couplings 2 148 

Table 16. — Flange Couphngs 149 

Table 17. — Compression Couphngs. Solid Journal Boxes 150 

Table 18.— Rigid Pillow Blocks. Plain Shaft Collars 151 

Table 19.— Angle Pillow Blocks. Safety Shaft Collars 152 

Table 20. — PuUey Proportions. Spur Gear Proportions 153 

Table 21.— Weight of Material .154 



CHAPTER I 

DESCRIPTION OF METHODS OF REPRESENTATION 

1. Probably the best way to describe a material thing is to make a picture of it, and a written 
language composed of hieroghi^hs would prove satisfactory^ if it had to express only what we sense through 
the eyes. To depict odors, sounds or emotions would severely tax such a language as reference to the 
ancient Egyptian monimients will prove. 

The written language of modern engineering construction has to deal chiefly with shape and size 
of material things. It is a picture language and its superiority over the language in common use wiU be 
quickly recognized, if one attempts to read a written description of a modern machine without the aid of 
an illustrative drawing. 

A perusal of legal documents wiU show how difficult it is to express an idea or fact concisely and with 
exactness. In the modern sciences, extended terminologies permit this. There is, of course, a special 
vocabularj^ of technical terms used by engineers and shop workmen, and it would be possible to wTite a 
specification describing each part of a machine so it could be built, but to write and to read such a descrip- 
tion would be a tedious and a costly process invohdng many chances for error. There was a time when 
construction was carried on in shops by oral directions from the foreman, or the workman made a part of 
a machine to suit his own notions, very much as some repair work is now done. If such methods had pre- 
vailed, the general use of our numerous modern contrivances would have been deferred to the remote 
future. 

2. An engineering drawing must describe the machine or structure completely, exactly and con- 
cisely that it may insure economy of time for the maker and the reader. [Most drawings used in engineer- 
ing work are made mechanically with instruments, because most of them can be thus made more eco- 
nomically. There are, however, many draT\Tngs which an engineer or draftsman has to make, where it 
would be very impracticable to make them with instruments. Such are the innumerable preliminary 



sketches used in designing, the incidental sketches made for illustrative or explanatory purposes, sketches 
of parts of existing machines and sketches for work of which no record is preserved such as repair jobs. 
It is also true that some desirable forms of representation which can be made well and quickly free-hand, 
become expensive when drawn with instruments. 

3. The problem in illustrative drawing is to produce a representation of an object having three 
dimensions on a fiat surface having only two dimensions. The difficulty lies in properly representing the 
third dimension. The different methods for accomplishing this, their underlying principles and their 
adaptation for mechanical and free-hand treatment will be considered. 

Nearly all simple objects can be represented without ambiguity by a single outhne drawing. A 
stick of wood looked at endwise tells nothing regarding its length. It might be a block or a long beam. 
By looking at it from some other point of view its true proportions are indicated. In the case of a sphere 
the outhne from any point of view is a circle. There are three ways of completing this representation. 
If we draw a circle and write "sphere" on it, the size and shape are defined. If we draw two circles and 
indicate that these are views from two different points, the object is defined. If we draw a circle and shade 
its surface to represent the light and shade effect on the original, the object is defined. Each method has 
its advantages dependent on the use to which the drawing is put. 

4. If a die is held close to the face, but far enough from the eyes to be seen distinctly, it will appear 
as in Fig. I , A. On closing the right eye it appears as at B and on closing the left eye, as at C. The fact is, 

we get a separate image of the object with each eye and if both eyes are open the 
two images are merged more or less into one. To test this, set up a card about ten 
inches high edgewise between B and C and look at the figures from the top edge, 
the card serving as a partition to shield B from the right eye and C from the left. 
These two images will always occur when both eyes are used, but the difference 
between the two is not noticeable, except when the distance of the object from the 
eye is small as compared with the greatest horizontal dimension of the object. A drawing like A would 
not be a satisfactory representation of the die, but either B or C would be satisfactory. We therefore 



B 



I I 



SZ^ 



Fig. I 



derive the conclusion that to make a satisfactory representation of an object, it should be drawn as seen 
with one eye. It is also true that if this drawing is to produce the same effect on the eye that the original 




Actual D/^aw/n^ 

ON PlCTUf?£ f'LANE: 



Fig. 2 



object did, it should be looked at with one eye, the drawing being held at the same distance from the eye 
as when made. 



10 



Stereoscopic photographs made in pairs and viewed in the stereoscope give an increased reaUty 
to the thu'd dimension. A similar effect is produced when a single picture is viewed with one eye through 
a conical tube or through the closed hand. 

5. Referring to Fig. 2, A, we have a cube ABCD-H resting on the right end of the top of a table 
OPQ. Let the eye be placed at E and interpose a transparent piece of glass KLMN between it and the 
cube. The cube is visible to the eye, because light is reflected from its faces and as these faces have differ- 
ent degrees of illumination, their bounding edges appear conspicuously as lines. We may consider that 
the light reflected from any point, B, on the cube to the eye passes along a straight line, BE, through the 
glass at some point b. If we mark this point, b, on the glass, it will shut off our view of the corner, B, of 
the cube which is in line with it. In the same way, we may mark the other points on the glass where we 
see the other corners of the cube. These points are now connected forming lines which appear to coincide 
with the edges of the cube. That is, line ab shuts off edge, AB, be shuts off BC and in the same way, 
the others. The cube could now be removed and the figure abcd-h would produce the same effect on 
the eye that the edges of the cube did. It stands in place of, or represents the cube. Such a drawing 
is called a Linear Perspective. It is designated Linear because it represents lines, but not the light and 
shade nor the color effect. 

Fig. 2, B, is the actual drawing, as it is on the glass plane. The 
transparent plane is called the picture plane. The line ES from the 
eye to the center of the object is called the line of sight. 

6. If in Fig. 2, A, the picture plane is revolved about the line 
X-Y as an axis, until it is perpendicular to the fine ES, the perspec- 
tive drawing would change to that shown in Fig. 3, A. Here the 
upright edges are not quite vertical and produce a false impression 
regarding the object. If they are made vertical, as in Fig. 3, B, 
the drawing will be an Artists' Perspective of the cube. 
7. Referring again to Fig. 2, A, suppose the eye to be moved along the line SE so that it is much 
further away from the object. Then the angles which the Ught rays make with each other at E would 




Fig. 3 



11 



become much less. If E were removed along SE to a very great distance, then the angle between the 
light rays would reduce practically to zero and the hght rays would become practically parallel. The 
drawing on the pictiire plane would be called an Oblique Projection. It is so called, because if we pro- 
jected, or threw on the picture plane, each point of the object by a series of parallel lines obhque to the 
picture plane, we should get the same result. 

8. If the cube in Fig. 2, A, were placed further to the left with its front face parallel to the pic- 
ture plane, the perspective drawing of it would be like Fig. 4, A. If an obhque projection were now made 
by removing the eye to a great distance, the drawing would be like Fig. 4, B. Such a dra'5\ixig is caUed 

a Cabinet Projection. Its peculiar featm-es are that one face of the 
object is shown in its true size and shape, while lines perpendicular 
to this face appear inchned at 45° and of one-half their true length. 

9. Referring again to Fig. 2, A, suppose the eye be removed to a 
great distance from the object along a line RE which is perpendicular to 
the picture plane. The hght rays from the object 
to E would then become practically parallel to RE 
and therefore perpendicular to the picture plane. 
The drawing on the picture plane would then become like Fig. 5 and it would be called 
an Orthographic Projection, because if the object were projected on the picture plane 
by hnes perpendicular to that plane, we should get the same result. The term 
projection is always understood to mean orthographic projection unless othemase 
stated. It is thus apparent that a projection drawing is merely a perspective drawing 
in which the eye is placed at a great distance from the object. 

10. In Fig. 6, A, the cube, ABCD-H, is elevated shghtly from the table and turned so aU its edges 
are obhque to the plane of projection. It is also placed so its upright edges are aU parallel to a side plane, 
not shown, but which is perpendicular to the table top and the plane of projection. If a projection of 
the cube is now made on the vertical plane, its actual shape will be like Fig. 6, B. If this drawing be com- 





Fig. 



12 



pared with Fig. 2, B, a marked similarity is noticed, although there are also important differences. A 
projection made in this way is the basis of an Axometric Drawing. 



Isometric PnojEcnof^ 




Fig. 6 



11. If the cube in Fig. 6, A, had been placed so that the three edges meeting at a corner, as for 
instance B, were equally inclined to the plane of projection, then the resulting drawing would have been 
like Fig. 6, C. This is called an Isometric Projection. Its peculiar features are that the three edges 



13 

meeting at B are 120° apart and equal in length. Any line of the drawing, as for instance, be, is shorter 
than the edge of the cube it represents. 

12. If a drawing were made of the cube, which was exactly like Fig. 6, C, in shape, but in which 
the hues be, ab, bg, etc., were each equal to the true length of the edge of the cube then we should have 
an Isometric Drawing. An isometric drawing is exacth^ hke an isometric projection, but larger. 

13. SoUds have three principal dimensions; length, breadth or width and thickness or height. 
These terms are apphed in various ways depending on whether the object is large or small, movable or 
fixed and other characteristics. The essential thing to remember is that these three dimensions are per- 
pendicular, each to the others. It might be difficult to agree on the length, breadth and thickness of so 
irregular a form as a potato, but three measurements could be arbitrarily assumed, which would have 
the essential feature of such dimensions, namely, mutual perpendicularity. In the case of most artificial 
forms, however, there is httle difficulty in selecting these principal dimension lines or reference axes 
of measurement. Generally they will be partty or entirely determined by the physical pecuharities 
of the object. The rectangular block and the circular cyhnder are the predominant artificial forms. 
In the former, the edges, and in the latter the axis of s\anmetry and two perpendicular diameters would 
be selected. In the case of the sphere, three perpendicular diameters would be chosen. 

If a draT\ing is to be useful as a guide in construction, it must satisfy the following conditions : 
First, it must give an idea pictorially of the shape of the object. 

Second, it must be of such a nature that aU necessarj^ dimensions and specifications can be appended. 
Third, when completed with all dimensions and specifications, the whole must be capable of being read 
with a minimum amount of study. 

14. To permit satisfactory application of dimensions, the object must be placed so its projections 
show the lines of the object in their true length. To accomplish this, the object must be placed so two 
of its principal dimensions are parallel to the plane of projection. The result of this is to lose the third 
dimension, so that nearlj' always two or more projections of the object are required. 



Third Angle 
Projection.^ 



Top }/ici^ fA \ 




F' 



G' 



H- 



G' 



Fig. 7 



15 

In Fig. 7, the object to be represented is a triangular pyramid JKL-0. It is placed inside a glass 
box ABCDEFGH, the back side of which is lacking. A working drawing for such an object should give 
the size and exact shape of the base, the altitude and the location of the vertex relative to the base. The 
pyramid is therefore placed with its base parallel to the top face of the box and this location brings the 
altitude parallel to the front face of the box. One side of the base, JK, is parallel to the face BCFG. 
The pyramid is now projected onto each of the five faces. The joints of the box along edges AE, BF, 
CG and DH are then broken. Keeping the front face, ABCD, stationary, swing the top, bottom and 
two side faces about their hinge lines AB, CD, BC and AD, until they come into the same plane with the 
front face, as shown. 

15. The projection figures on the four revolved faces are now grouped about the central projec- 
tion on the front face and certain features of their relations should be noted. 

Considering the central projection, or front view, the principal one, it is seen that the view obtained 
from above the object, that is the top view, is placed above the front view; the view of the right side is 
placed at the right; the bottom view below and the left view at the left of the front view. This is a 
logical arrangement and it is called third angle arrangement, or Third Angle Projection. 

This is the arrangement of views used in nine-tenths of the drafting rooms in the United States. 
The other arrangement most used is known as first angle projection. With this method of grouping, the 
top view is placed below the front view, the bottom view above, the right view at the left and the left 
view at the right. It is entirely, illogical, renders a drawing more difficult to construct and to read and 
has advantages in only a few instances. First angle projection is used for shop di'awings in Great 
Britain, on the continent and by the other tenth of draftsmen in the United States. 

16. It should be noted next, that any point of the object, as the vertex 0, will have its projections 
in the front, left and right views, that is 0^, 0* and 0^, on the same horizontal line. Also any point, as O, 
will have its projections in the front, top and bottom views, that is, 0^ 0^ and G" on the same vertical line. 
This relation between the views is a very important one, and it facilitates greatly the making and read- 
ing of the projections. 



16 

17. Inspection of the projections shows that two views, the front and top would suffice in this 
case to represent the object, and accommodate all necessary dimensions. Thus the top view shows the 
exact size and shape of the base and the location of the vertex, while the front view gives the exact altitude. 
Though two views are really necessary here, for some objects, one view would suffice. On the other 
hand, for some very irregular machine parts, five views supplemented by auxiliary sections, dotted lines 
and specifications are none too many, to make them intelligible. 

18. The names used in Fig. 7 for the different projections are those commonly employed. Others 
are also in use for architectural drawings and Descriptive Geometry. They are given in the following table. 

Common Name Architectural Drawings Descriptive Geometry 

Front View Front Elevation Vertical Projection 

Top View Plan Horizontal Projection 

Right View Right Elevation Right Profile Projection 

Left View Left Elevation Left Profile Projection 

Bottom View Plan Aux. Horizontal Projection 

CHAPTER II 

SHOP DRAWINGS AND BLUE PRINTING 

19. A working drawing is one used by a workman in actually making the machine or structure 
which it represents. 

20. While many of the methods of representation described in the preceding chapter might be 
used for working drawings, the one last described is usually employed. Though somewhat deficient pic- 
torially it has the foUowmg advantages. The process of making the projections is easily explained and 
generally understood. The drawings are composed principally of horizontal and vertical straight lines 
and circles, all of which are easily made with ordinary instruments. The large number of views available 
makes it possible to avoid the confusion of lines and figures which occurs when one view only is used. 



17 

21. There are two kinds of working drawings. A detail drawing shows each piece by itself with 
complete dimensions and specifications for its construction as shown in Fig. 9. An assembly drawing 
shows all the parts of a machine or stinicture assembled, or put together : or it may show a group only 
of parts put together. A drawing of an engine would illustrate the first, while a drawing of the connecting 
rod of an engine would illustrate the second. An assembly drawing may be used in a pictorial way, 
merel}', to give a general idea of the machine, in which case, much of hidden detail is not indicated and only 
the principal dimensions are given. Such a drawing may be used for assembling or for erecting the ma- 
chine and then eA"erji:hing is shown in greater or less detail, but with only a few dimensions. Aji assembly 
drawing may be used as a shop drawing for actual construction, and then complete dimensions are given 
for every detail. It is obvious that only the simplest machines, tools or structures could be thus drawn. 
A shaft hanger or a monkey wrench would be illustrations. Such a drawing has an advantage over a 
detail drawing, in that there is less chance of error, both in making the drawing and in making the parts. 
In the case of the draftsman, the drawing helps to check the dimensions and, in the case of the workman, 
he sees how the parts fit together. If a machine is made on the interchangeable system, this last feature 
is of no particular value. 

22. Scale. Drawings should be made large enough so the}" can be easily and accurately read 
when covered with dimensions. For convenience in fifing, most drafting departments have adopted 
standard sheet sizes, which are particularly adapted to their special line of work. 

It is often desirable to place on one sheet all the parts of a machine constituting a natural group ; 
for instance, all the parts of the tailstock of a lathe; or all the forgings; or all the castings. These con- 
ditions, therefore, will usually determine the scale. A bridge is drawn to a greatly reduced scale, the 
general run of machine parts are drawn full size, while instruments or machines with exceedingly small 
parts, like those of a watch, should be drawn larger than full size. 

23. The scales in common use are as follows, 12 inches, 6 inches, 3 inches, H inches to one 
foot for ordinary details of machinery; 1 inch, f inch, =| inch, | inch, I inch and I inch to one foot for 
larger structural work. A drawing made to a scale of li inches to one foot is one in which Ih inches 



18 

on the drawing represents one foot in the object; that is, the drawing is I of full size. Full size is a 
very desirable scale, especially for the designer when sketching small details, because it conveys an exact 
idea of the size of the part and there is also less liabihty of errors in dimensioning. 

Some drafting rooms are provided with large vertical boards ruled with squares and used for full 
sized layouts. Such a layout is particularly useful in designing a new machine. 

SELECTION OF VIEWS 

24. Select those views and the least number of views that will completely and clearly represent 
the object. Do not use two views, if one will suffice. If more than one view is necessary, one of them 
should be the front view, as this makes it possible to project from points in one to corresponding points 
in the other projection by horizontal or vertical projecting lines. In Fig. 7 the object might have been 
placed so as to make a front view of what is now the right view. A corresponding change in the posi- 
tions of the other views would have been necessary. 

A judicious use of dotted lines or of sections will often permit a reduction in the number of views, 
as is explained in Sections 29 and 30. The pipe fittings in Fig. 1 1, the Latch Handle in Fig. 8, A, and the 
Spur Gear in Fig. 18, illustrate this. On the Lag Screw in Fig. 10, by specifying Sq. Head, an additional 
view is avoided. Also in the Anchor Bolt for concrete in Fig. 10, by giving the letter d after the if" 
dimension, a round bar is indicated thus making one view sufficient. 

25. While limitations of space or the clearness of the drawing may sometimes decide otherwise, 
yet the desirable and the customary front view is that view which shows the object most characteristically 
and in a natural position. For a building, it would be the facade; for a bridge, the longitudinal view; 
for a pulley, the view showing the radiating arms ; for a machine, the view a workman gets as he stands 
at work before it. Some objects have no characteristic view, others have several and a moving part 
like the crank on an engine may have many natural positions. These are exceptional. 

26. It is allowable to have one view showing the object with a part removed as in the Cylinder 
Cap, Fig. 9, while another view may show it entire or with a different part removed as in the Worm Gear- 



19 

ing, Fig. 18. To condense a drawing, it is often desirable to break out a portion as in the Pulley, Fig. 9. 
Under Broken Ends in Fig. 8 is indicated how to break rods, pipes, structural steel, etc., so as to suggest 
the shape of the cross-section. 

An auxihary view is sometimes needed which cannot properly be grouped with the other views. 
Its location or relation to the others must be very definitely specified by projecting lines or otherwise. 

27. When two pieces are exactly alike except in some minor detail or diaiension, it is often possible 
to make one drawmg serve for both, as in the Hoist Arm Yoke, Fig. 9. 

28. Threaded Parts are so nimierous that to save the draftsman's time they have been conven- 
tionalized. The same is true regarding Riveting in Structural Work, and the Fittings in Pipe Systems. 
These are represented in Fig. 10 and Fig. 11. 

USE OF DOTTED LINES 

29. Some draftsmen show all hidden edges, but this is plaioly a mistake, for in many instances 
it produces only a confusion of lines and obscures the meaning of the dra-n-ing. Hidden edges should be 
shown, only when they contribute to the clearness of the drawing or give it a more finished appearance. 
Thus in Bevel Gears, Fig. 18, the dotted lines complete the representation partly shown by the haLf section. 
See also Section 81 for the proper way of making a dotted line. Figures 9, 10, 11 and 18 illustrate the use 
of dotted fines. 

USE OF SECTIONS 

30. A slice or section is used to show the contour of an irregular shape or of a shape not clearly 
shown by dotted lines. The section of the puUey arm, Fig. 9, and of the Latch Handle, Fig. 8, A, are illus- 
trations. The section may be specified in am' one of the three ways shown in Fig. 8, A. A section of this 
kind shows nothing more than the figure cut from the object by the sectioning plane. 

31. A sectional view is one which shows not only the cut surfaces, but everything back of them 
also. The chief use of a sectional \aew is to explain the internal construction of the object. In Fig. 8, B, 
is an illustration of this. Note that the centerJs not cut, as there is nothing inside of it to be exi^lained. 



CAS T If^ON 




^v/?/^p^— grgg^, Use of Sections 



BROKEN Ends. 



Bkick 

W//y///M 

Hubble 



Wood 





Concrete 









.> »a ' 



' ,^ . 



:0 



5 • i3 » 



^ V'_'« , '-: » -a. 



;,^ <i 



>'<i^f^-^;^:^^ 



■» fl 



o'z-L^A:^ 



jiii 



WATEFi 



I r^ 




V, 



BEAM 



N 



Angle 




Tee 



r^ Max. Space Width 

^ FOR A QIVEN WIDTH 



I I 



Section 
AT MN 



Z Bar 



A Sectional i/'/Eyv 

CfiOSS LiNINq or O/F-rSffEAfT PAftTS 

OF THE SAr^E Piece /s the Same. 



Section Lininq MciT /vot- 

Cfl03.5 0/^E/V.5IO/\/ Piqi//T£S . 



OF APEA. 





Pic s 



21 

Sectioning planes may be taken in any way to facilitate the explanation of the object, but they are usually 
taken parallel to some one of the planes of projection. Unless the location of the cutting plane is perfectly 
obvious, it should be indicated by its projection on the plane to which it is perpendicular, where it will 
be shown as a line, marked as in Fig. 8, A. 

A common exception to the rules of sectioning is shown in the Pulley, Fig. 9. 

32. Sometimes when it is not desirable to remove the part of the object in front of the sectioning 
plane, a dotted section may be used as in Fig. 11 , V. 

33. Section Uning or cross hatching may be at any angle, so long as it is not parallel to the bounding 
lines of the surfaces sectioned. The angles generally used are 30°, 45° and 60°, which taken both ways 
give six directions. If two different pieces come together in the same section, as in Fig. 8, B, a different 
angle should be used for each piece ; but for different parts of the same piece, even though disconnected, 
the same sectioning will be used. Width of spacing is determined by the smallest sectioned part of a given 
piece and large areas may have wider spacing than small ones. Fig. 8, C, shows satisfactory spacing for 
different areas. 

34. The kinds of material used in construction have multiplied to such an extent in recent years, 
that it is no longer feasible to have a distinctive symboUcal section lining for each. In Fig. 8 are shown 
some of the kinds which are in use chiefly in a pictorial way. On a working drawing these are seldom used, 
plain sectioning and definite printed specification of the material being the custom. 

35. Section lining is one of the most tedious parts of a draftsman's work. To secure uniform 
spacing on large areas, a special instrument is often used. For ordinary work, spacing by the eye is 
sufficiently accurate. Make the first few spaces carefully and then look back to them frequently for a 
gage on the other spaces, rather than at the last spaces made. For free-hand sectioning, the slant from 
the upper right to the lower left is the one to be preferred for a right handed draftsman. 

USE OF CENTER LINES 

36. As has been pointed out in Section 13, nearly all artificial forms have some line or lines with 
regard to which they are symmetrical. All turned forms have an axis of revolution, links such as the 



I5'x4" Pulley ,., 



Sp/ral Gear Shaft 

Oa/£- MACH.St. ^2^ 



^OoyerAiLMEY 



/6Pi. 




-> 



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Name 


No. 
R£<f. 


MAT. 


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23 

Rocker Arm, Fig. 32, have an axis line connecting centers of holes. In a steam-engine, there is the axis 
of the cyUnder, the axis of the crank shaft, the axis of the connecting rod and various others. Ever}' drilled 
or bored hole, ever}'' screw, bolt, gear and pulley has an axis. In making a drawing these lines are in^'ari- 
ably drawn first, because they are very useful in making measurements. They are called center lines 
in the drawing and are usuall}' shown as dash and dot hues. They are base lines for measurements which 
the workman also must use in lading out his work. In the Bevel Gears, Fig. 18, they are used to indicate 
symmetrj', for dunensioning the angles and for distance between shafts. In the Pulley, Fig. 9, they indi- 
cate symmetry only, and this is then- general use for isolated shafts, bolts, screws, etc. T\Tiile they are 
useful in making the drawings in this last case, they serve no purpose for dimensioning and for this reason 
are often omitted in such drawmgs where the}' would seriousl}' interfere mth dimension figures or speci- 
fications. Note the screws in Fig. 10. 

A center line is used for the pitch line of gears as in Fig. 18, and for bolt circles as in the Cylinder 
Cap, Fig. 9. 

DIMENSIONS AND SPECIFICATIONS 

37. It has been suggested that the projections in a drawing are important only as a suitable frame- 
work to which dimensions may be attached. This is an extreme view, as any draftsman who neglected 
his projections would quickly discover. Projections are secondary' to dimensions just as the whole draw- 
ing is secondary to the thing it represents and just as the machme it represents is secondary to its product, 
and so on indefinitely. It is true, however, that small errors in projections are frequent and sometimes 
permissible, though never desirable, while an error in a dimension may be fatal. The projection is used 
for illustration, while the dimension is used for measurement in construction. On this account, the 
dimensions and specifications of a drawing are its most important part. 

38. Three questions arise. ^\Tiat dimensions should be put on a drawing? \Miere shall they be 
placed? How are the}' expressed? Unless the draftsman has had actual experience with, shop methods 
of consti-uction, he will not be very successful in his selection of proper dimensions. His fii-st inchnation 
is to put on such dimensions as would enable the drawing to be duplicated. He must rather keep in mind 



24 

the thing to be made, the tools the workman will use in laying out and measuring his work and the various 
machine operations to be performed. Constant study of approved shop drawings will give considerable 
information, conferences with the workmen will also be enlightening, but actual working on the machine 
in the shop is the best training for this part of the draftsman's work. 

The principal tools used by the shop workman are the two foot rule, steel scale, calipers, dividers, 
square, trammel points, straight edge, protractor, surface gage and other gages for threads, drills, wire, etc. 

The principal machine operations are turning, boring, drilling, milling, planing, and grinding. Hand 
work such as filing, chipping and scraping should not be overlooked. 

Besides the workman's tools and machines there are other considerations. For instance, many 
years ago, the shop workman was a man of extended mechanical experience, while to-day he is more or 
less of a machine; oftentimes against his will. Instead of having an intimate knowledge of the machine 
he is helping to build, his knowledge often extends only to a part which he regularly makes. A drawing 
must therefore be made minutely specific and little should be left to the discretion of the workman. To 
this end, it is advocated that the dimensions which he will use directly should be put on the drawing, so 
that he need expend no intelligence in adding up partial dimensions. Thus in the Spiral Gear Shaft of 
Fig. 9, the workman in turning from the f end to the If" shoulder would like a dimension equal to the 
sum of If", 1^" and 4^". Such a dimension is seldom given by the draftsman, because he is interested 
onlj^ in the direct measurements which must be correct to permit fitting the piece to the parts it adjoins 
in the machine. If such a dimension is given, it should be in addition to those which are direct. 

If there are finished flat surfaces on the piece, dimensions should be based on these and the same 
is sometimes true regarding curved surfaces. Thus in the Pulley, Fig. 9, the thickness of the rim is based 
on a finished curved surface, but the thickness of the hub is not given by a measurement from the "bore." 

Location of parts of a piece are often made by reference to a center line, but care should be taken to 
see that this is a satisfactory way of locating. Such a method may be desirable oftentimes for the pattern- 
maker, but might be entirely inadequate for the machinist. 

It is impossible to lay down an invariable rule for the selection of dimensions, but the following is 
a good general guide. Put on those dimensions which will be common to fitted parts and which must 



25 

be exactly right; also as far as possible, give those dimensions which the workman will use in setting his 
tools to make the pattern or to machine the surfaces. 

39. The parts which go into machines and structures may be divided roughly into the following 
classes : Machine and hand forgings, castings, parts made in the screw machine from rod or bar stock and 
those numerous parts which are standard or semi-standard in form, such as bolts, keys, wire, pipe, sheet 
metal, etc. 

Fig. 9, A 8, shows a simple forging with no machining called for except in drilling holes. If any of 
the surfaces were to be milled or planed it would be indicated by an/ mark, so the blacksmith could make 
the part thicker than called for by the dimension. In machining, the part would be thinned to the stated 
dimensions. Dimensions are selected as follows. For size of bar stock, f " thick and 2" wide. As all 
the fitting depends on the surfaces shown edgewise at AB, AC and BD, locations are given relative to these 
surfaces. Thus inside distance between end arms of 5|", distance from end of arm to inside of back 
21", distance of ear from inside of end arm If". Dimensions of thickness, length and width of ear are 
given. Location of bolt holes is given from surfaces AB and BD. Specification of size and pitch of tap 
is given. Note that a drilled hole is located by its center, because it is necessary to prick punch a point 
on the metal to take the point of the drill in starting. See also Section 27. 

40. An inspection of this drawing shows that the Yoke is composed of four parts. Dimensions 
had to be provided therefore, to give the size of the different parts and to give their relative locations. 
This is true of nearly every piece used in a machine or structure. 

41. The drawing of the Pulley, Fig. 9, will illustrate the dimensions needed for a easting. As the 
Hoist Arm Yoke was dimensioned for the blacksmith and the machinist, so here the pulley must be di- 
mensioned for the pattern-maker and the machinist. The pattern-maker will need diameter, face width, 
thickness, crowning and draft for the rim : diameter of bore, diameter, length and draft on the hub ; number 
of arms, section of arm, width and thickness of arm at rim and at hub; relative position of hub and rim 
and dimensions of rib at root of the arms. To allow for finish the surfaces to be machined are to be marked 
/. Note that the f is put on the surface where it projects as a line. 



26 

The dimensions needed by the machinist are as follows. Diameter and length of bore, dimensions 
of keyway; diameter, face width and crowning on the rim. 

Fillets and rounded corners should be shown on the drawing, but the size is not usually dimensioned 
unless they are of large radius and of importance in the design of the part. 

On small pulleys the inside diameter of the rim is often given, instead of run thickness. 

42. The Spiral Gear Shaft, Fig. 9, illustrates dimensioning for a piece turned from round stock. 
Here, all the dimensions are for the machinist. An overall dimension tells him how long a piece of stock 
to cut off and avoids the necessity of his adding the partial dimensions. This piece is made up of cylin- 
drical sections of various lengths. The diameter and length of each is given. Where a section is ground 
to size, the same is specified and it is noted that one part is ground standard, that is to exact gage, another 
is finished a half-thousandth large, while a third is ground one and one-half thousandths small. The length, 
diameter and pitch is given for each threaded part, also the kind and size of each key. No finish, as such, 
is specified because the shaft has to be machined from a much larger piece. If a large spindle or shaft 
were forged approximately to size before machining, then of course, finish marks would be used. Note 
also the discussion on these dimensions in Section 38. 

43. An illustration of the dimensions necessary for a part which has been standardized commer- 
cially is the Cap Screw or Tap Bolt of Fig. 10. Unless something irregular is required in the thread or 
head, it would be sufficient to give the diameter, length under head to extreme point and length of threaded 
part. See also Chapter III on Miscellaneous Details for other examples. 

44. A dimension line consists of two arrows with their shafts in the same line and their points 
terminating on the lines between which the measurement is taken. The measurement which is given by 
the figures is from point to point of the arrows. The following rules and suggestions give the general 
practice with regard to character and placing of dimension Unes and figures. Figures 8, 9, 10 and 18 
furnish illustrations. Note exception to this in Section 173. 

45. Dimensions should not be crowded on a projection nor around it to such extent as to make the 
reading difl&cult. 



27 

46. To distinguish dimension lines from the outhnes of the projection, make the former about one- 
half the width of the latter. Dimension lines are often made with red ink, so as to produce contrast in 
the blueprint between them and the lines of the projections. 

47. Make arrows sharp pointed and not blunt. 

48. If there is not space for the dimension on the projection, it may be carried to one side by 
extension lines as in Fig. 8, C. 

49. Draw extension lines first where they are needed, then the dimension line leaving a break 
near its middle (or at one side when necessary) for the figures. Put on arrowheads next and figures last. 

50. If the space for the dimension is very limited use one of the methods shown in Fig. 8, C. 

51. Extension hues should not quite touch the lines they extend, as they would become confused 
with them. 

52. Extension lines should be of the same weight as dimension lines. 

53. A line of the projection must never be used as a dimension line. 

54. A center line must never be used as a dimension line. 

55. When the dimension Une gives the radius of an arc, use an arrowhead at the arc end only. 
See Friction Pawl Shoe in Fig. 9. 

56. When several dimensions are parallel, the longest is placed furthest out to avoid confusion of 
extension and dimension lines. See Cylinder Cap, Fig. 9. 

57. Dimension lines for an angle are usually circular arcs with centers at the vertex of the angle. 
See Fig. 18. 

58. Dimension figures give the actual size of the measurement indicated, although the drawing 
may be much smaller than full size. See Pulley, Fig. 9. Mark approximate dimensions thus, 3' — 9"± 
See Fig. 21. 



28 

59. Dimension figures should read with the Hne and from the bottom or right end of the sheet for 
horizontal and vertical dimensions. For oblique dimensions, practice varies, but some draftsmen put all 
such figures horizontal. 

In the case of explanatory drawings for tables we have an exception to the general rule. See tables 
at the back of the book. 

60. Figures must be large enough to be perfectly legible in the blueprint which is often made from 
the drawing. They should be very distinctly formed. If space is too limited, take the figures to one side 
with an arrow to indicate where they belong. 

61. The division mark for fractions should be parallel to or in line with the dimension line. 

62. Many draftsmen specify all measurements up to 24" in inches and those above 24" in feet and 
inches. Practice is quite variable in this matter and diameters of turned forms especially are often given 
in inches even though of very large dimensions. Thus, a 32" shaft, a 72" pulley, a 54" cylinder. 

63. If all the dimensions on a sheet are in inches, the inch mark on figures is often omitted. 

64. If some dimensions are in feet and inches, then the foot and inch marks should be used and the 
figures separated by a dash. Thus, 2'-7", 3'-0", 7 ft.-5". 

65. If the size of a fillet or of a rounded corner is of importance, its radius should be given as in 
the Pulley, Fig. 9, the figures being followed by the letter R or by Rad. 

66. If the whole of a dimension line is not shown, some specification must be added to explain 
its extent. Thus in the Pulley, Fig. 9, the figures for the diameter are followed by Diam. 

67. If the size of a part is changed after the drawing is completed, it is customary to change the 
dimension figures, but not the projection. For instance, suppose the hub diameter of the Worm Gear 
in Fig. 18 were changed to 1|". Cross, but do not erase the IJ" and specify below, "changed to I5". 

68. Dimensions for angles may be specified by the number of degrees and tenths or by the amount 
of vertical rise on a given length of horizontal base. The former should be used where the measurement 



29 

is to be made with a protractor, the latter is generally more convenient for the pattern-maker and is 
always used for structural work, and the pitch of pipe lines. See Fig. 21. 

69. Dimension figures should never be crossed by a line, nor placed so as to interrupt a line of the 
projection, nor an extension line. Note also the break in section lining about figures and lettering. See 
Figures 9 and 18. 

70. Give diameters of circles and the radius of a circular arc less than a semi-circle. If the location 
of the center of a circle or arc is not indicated by lines of the drawing it should be definitely located and 
dimensioned. 

71. Do not dupUcate a dimension given in another view, except for purposes of identification of 
a part otherwise not easily distinguished. 

72. Dimensions should be placed where they will be found quickly by the workman. They can 
generally be arranged in natural groups and should be put on one view as much as possible. Thus in the 
Pulley, Fig. 9, all the hub and bore dimensions form a group and are on the same view. The kejTvay 
dimensions are shown in the view where all can be put on. For the lengthwise partial dimensions on the 
Spiral Gear Shaft, Fig. 9, an arrangement very nearly in a straight line is desirable. 

73. Supplementary^ to the dunensions is the printed matter that accompanies the drawing. The 
name of the piece, usually some identification number or symbol, the number of pieces required for one 
machine or structure, the material, the kind and extent of finish, heat treatment such as tempering and 
any other pertinent and necessar}' facts are grouped together above or below the drawing to form a sub= 
title. See Figures 9 and 18, for examples. 

74. Notes are also added to explain special details, but these should be exactly definite and as 
few as possible. See notes on Bevel Gears and Spiral Gears, Fig. 18. 

75. Drive, force and shrink fits should alwaj's be specified. 

76. If a piece is hardened, tempered, case hardened, blued, nickled or oxydized it should be noted. 

77. Specifications are often made by giving name of manufacturer or the trade name or number by 
which he designates a macliine oi- part. Thus, No. S25 Ley Bushed Chain. 



30 

NOMINAL SIZES 

78. Specifications for much of the material that is used in construction are given by gage size, 
nominal size or size of one or more important dimensions. Some of the commonest of these are as follows: 

Belting. — For leather belts, give width in inches and the number of thicknesses. Thus, a 6" double 
belt. For cotton and rubber belting, give width and ply. Thus, a 4"-3 ply rubber belt. 

Chain. — For hoisting chain, give the diameter of rod from which it is made. For transmission 
block chain, give the circular pitch and the width of block. Thus, pitch 1 "-width f". For transmission 
roller chain, give the circular pitch, the width between inner links and diameter of roller. Renold chain 
is specified by circular pitch and the nominal outside width. Under 1" pitch the actual exceeds the nomi- 
nal width, but above that pitch they are alike. 

Drilled Holes. — When of small diameter, give size by Drill Gage number. Table 5. 

Hangers, Wall Brackets and Pillow Blocks. — These are designated by the diameter of shafting they 
support. The drop of hangers is also given. 

Machine Screws. — Give diameter by Screw Gage number, number of thread and length. Table 5. 

Pipe. — For standard wrought iron pipe, give the nominal inside diameter. Table 11. For spiral 
riveted pipe give inside diameter and thickness by B. W. G. 

Pulleys. — Give diameter, face and bore in inches. 

Rod and Bar Stock. — Give dimension between flats for square, hexagon and octagon sections. 
Give width of flat on half round. 

Rolled Sections. — See Section 169 for I beams, channels, etc. 

Rope. — Give largest diameter over strands. Number of strands and wires per strand are some- 
times added. 

Shafting. — Turned shafting for transmission purposes is often designated by its nominal diameter, 
the diameter before turning. Thus, by 2" turned shafting would be meant shafting having an actual 
diameter of Ijl". To avoid all chance for error the actual diameter should always be specified. 

Sheaves. — Give the diameter at the pitch line of the rope. 



31 

Sprockets. — Give pitch diameter. 

Sheet Metal. — Thickness is usually given by gage nmnber or in thousandths of an inch. Plate is 
also designated bv thickness in ^-ulgar fractions, thus, j^" and by weight in pounds per square foot. 
Fig. 14. 

Tapers. — Specify by the number and the standard, thus, No. 16 B. & S. Table 13. 

Tubing. — Give outside diameter and thickness by gage number. 

Wire. — Give diameter by Wire Gage number or in thousandths of an inch. Wu-e used for electrical 
purposes is often designated by its area in circular mils. A mil is TTi\ro of an inch. A circular mil is 
the area of a cu-cle whose diameter is one mil. Table 5. Fig. 15. 

Wire Cloth. — Give the number of meshes per lineal inch and the gage number of the wire. 

Wood Screws. — Give the nmnber by Screw Gage and length. Table 5. 

79. Specifications for the common forms of fastenings, such as are shown in Fig. 10, are given in 
Chapter III. 

LINES OF THE DRAWING 

80. The various lines used in working di-a wings are shown m Figures 9, 10, 18, 20, 21, 22 and 23. 
General practice is to make all lines with black ink, but many draftsmen prefer red for all lines except 
those of the projections, because the two sets of hnes are thus easily distinguished in the drawing and in 
the blueprint made from it. There are three features to be considered in determining the chai'acter of 
these Unes. 

They should be easily distinguished from each other in the original drawing and in the blueprint, 
and should not consume too much time in the making. 

81. The visible lines of the object are shown bj' continuous or full lines not less than ^/' in width 
for ordinary drawings. 

Hidden lines of the object are represented by dotted lines not less than ^" in width. The length 
of dot will varj' -n-ith the size of the drawing and length of the hne. The space between dots or dashes 
should be just long enough to show that the line is broken. The end dot should start at the full line. 



32 

provided it does not thereby become a continuation of some other Une. Otherwise, start the dotted hue 
with a space. See dotted Unes in Bevel Gears, Fig. 18. 

Center lines may be full lines or of alternating dots and dashes. In either case they should not 
exceed h the width of lines of the projection. 

Extension lines may be full lines or dash lines and of the same weight as center lines. They should 
not quite touch the lines they extend. 

Dimension lines are usually made as two long dashes with a break for the dimension figures. For 
long lines they may be several long dashes. Width of line should be same as for center lines. 

Shade lines should be at least twice the width of the lines of the projection. 

Other lines may be combinations of dot and dash lines. 

GENERAL ARRANGEMENT OF A SHEET 

82. The general arrangement of a sheet of details will be similar to that of Fig. 9. Each part with 
its projections, specifications, dimensions and sub-title should constitute a group somewhat separated 
from the others, so as to be easily picked out by the eye. 

83. The title of a sheet, described in Section 299, will usually be placed in the lower right hand 
corner. It will provide a variety of information according to the system in use. 

84. Near the title is often placed a Bill of Material similar to that in Fig. 9 and Fig. 21. It is to 
facilitate the work of order and cost clerks. Many prefer a different order by which the number of pieces 
required is given first and the name of the piece second. 

85. There are usually placed at the lower right and upper left hand corners numbers or symbols 
to designate the sheet and its contents for convenience in filing, indexing and reference. 

REPRODUCING DRAWINGS 

86. Drawings are commonly reproduced for the shop by blue=printing. If a drawing is to be thus 
reproduced, it should be made on tracing cloth, a thin, translucent, specially prepared linen or on thin 



33 

paper such as linen bond. If tracing cloth is to be used, the drawing is first made on paper with pencil 
in the usual way. The tracing cloth is then stretched tightly over the drawing and thoroughly tacked 
down onto the board. One surface of the cloth is usually glossy and the other side dull. Both take ink 
equally well, but some prefer the dull side as it can be pencilled on. \Miichever side is used, the surface 
should be sprinkled with a httle ground chalk and rubbed over with a cloth. This is done to remove greasy 
places which do not take the ink well. The drawing is then inked as if on the original sheet. The natural 
tendency is to use fine lines on a tracing, because it is so easy to make them. This is entirely wrong as the 
fine ink lines do not print out clearly, unless they have been made with hand ground ink. It is therefore 
best to use the heaviest ink line possible and this wiU be determined by the closeness of lines in the smallest 
details. 

If thin bond paper is used, the drawing is pencilled and inked in the usual way. 

87. To print, the tracing or bond paper drawing is put in a printing frame with the ink fines next 
to the glass and the prepared print paper is laid on it, the sensitized surface bemg put against the drawing. 
The drawing is now exposed to the sun and aUowed to print until it is possible to see just the least dis- 
coloration under the ink lines. This part of the sensitized surface having been protected from the fight 
should retain its original color. The print is taken from the frame and washed thoroughly in a sink of 
clean water for about a half hour after which it is rinsed and hung up to dry. 

88. The begumer nearly always overprints and thus gets poor lines. If the paper is fresh and the 
exposure is right, these should be a clear white. In washing the print, be careful that air bubbles do not 
collect on its surface as they will cause spotting. Also be careful not to spatter wash water on the draw- 
ing as it causes stains which cannot be erased. 

89. It is sometimes desired to make alterations in a bluepruit. The white lines can be obfiterated 
by rufing them with blue ink. WTfite lines can be made on the blue surface by using a solution of common 
washing soda in the pen instead of ink. 

90. Another process, known as the negative=positive process is sometimes used when it is desired 
to get prints just like the original drawing instead of reversed ui color. In this process, a special paper is 



34 

used which requires more manipulation than the common blueprint paper. Briefly, the method is this. 
The drawing is put in the frame, its blank side against the glass so that the sensitized surface of the print 
paper comes next to the ink hnes. The resulting print is negative in color and reversed in position. After 
developing, fixing, washing and drying, this negative print is put in the frame with its printed surface up 
so that the sensitized surface of a fresh piece can be in immediate contact with it. The print obtained this 
time is reversed in color and position with respect to the negative and is therefore like the original. By 
this process it is possible to make sharp, clearly defined prints even from drawings which are on heavy 
and almost opaque paper. The exposure is of course a prolonged one. Ordinary blueprint paper, if 
fresh, will give fair prints by this process. 

CHAPTER III 

MISCELLANEOUS DETAILS OF CONSTRUCTION 

Many of the simpler parts used in construction are common to all or most machines and structures. 
These will be considered at some length in the order of then* arrangement in Figures 8, 9, 10, and 11. 

TYPES OF SCREW THREADS FIG. 10 

9 1 . The Sharp Vee is used to only a limited extent, as it is difficult to keep taps and dies for it in 
condition. The sharp edge of the V wears down and approaches the shape of the U. S. Standard Section. 
Its lack of clearance makes it difficult to fit, if cut in the lathe. 

92. The Sellers or U. S. Standard is like the Sharp Vee with the point of the triangle flattened 
I of the height, at top and bottom. This is the thread in common use in the United States. Depth is 
.6495p. 

93. The International Standard adopted by the metric countries is not shown here. It is exactly 
the same shape as the Sellers thread except that the point of the V at the bottom of the thread is rounded 
■^ of the height. This is an improvement over the Sellers section, in that it provides clearance and facil- 
itates fitting. 



Types of Screw Thf^eads Con\/entional ScrevV'S 

Sharp Vaa SeuLets ok U.S. Stand. Vee-R.H.-Sih^le Square Doubj.e 



C0N\/ENriONAL THREADED HoLJiS 
A B C D E F 




■^ WA5HER 



■^S£ HAfli 

V-ti 



CAS£ HAf>o. 




A 

(F 


NCHOfi BOLT-S '*~Jz 




Of^ CoNCflETE '^^ 


H£X. 


Ill 




4 .. \ 
<> s' 






* 4- ''^ 




'' 



;jr G/B Head /fEr 



"> Fo^ Stoue 



TAPEfl -^ TO/2 \ 



Fig. 10 



3(5 

94. The Whitworth, or English standard, has an angle of 55° and the point of the V is rounded top 
and bottom ^ of the height. Depth is .64p. 

95. The Buttress thread gives a form of great strength where the load is always in the same 
direction. Its friction is low and it is easily fitted. It finds application in Bench Vises and Screw Jacks. 
Depth is |p. 

96. The U. S. Buttress is a modified form of the preceding used by the U. S. Government for 
breech blocks of guns and for armor plate bolts. 

97. The Square thread is used for power transmission screws where large pressures are applied. 
Its friction is low, but it is expensive to fit. Dimensions as given in the figure are modified a few thou- 
sandths of an inch to procure easy fits. 

98. The Acme thread is used for screws like the lead screw on a lathe. It has some of the good 
qualities of both the U. S. Standard and the Square threads. It is often called the Powell thread. Di- 
mensions as given in the figure are modified a few thousandths of an inch to procure easy fits. Exact 
depth is |p+.01". . 

99. The Knuckle thread is useful where a thread is liable to be bruised, as it will stand many 
knocks and yet work in its nut. Depth is -|p. 

100. Pipe Thread, not illustrated, has a 60° Vee rounded slightly at top and root, and a taper of 
1 in 32 measured on a radius. 

CONVENTIONAL SCREWS FIG. 10 

101. The true curve of the edge of a screw thread is a helix and this, of course, cannot be drawn 
every time a thread is represented. Various conventional representations are therefore used which show 
the thread with more or less accuracy and save the draftsman's time. Those shown at A, B, and C are 
the ones commonly used. The thread lines are drawn at a slight inclination approximately that of the 
actual thread of the same pitch. The spacing is also approximately true. Note that the short lines are 
made heavier. At C is a form, useful where the space will not permit the intermediate lines. 



37 

102. In the Vee R. H. Single screw, the thi-ead makes eight complete turns or wraps about the 
cyhnder in one inch. It is therefore called a No. 8 thread or an 8 Pitch thread. The linear pitch of the 
thread is really I", or the distance between centers of two adjacent Vees. In the Sq. L. H. Sing, screw, 
is shown a thread in which the linear pitch is I". There are four wraps in one inch and it is called a 4 
Pitch thread. 

103. In the Square Double screw, two distinct threads are wound on the cylinder, as indicated. 
Each wraps around the cylinder twice in one inch and each is really a 2 Pitch thread. The distance be- 
tween adjoining threads, however, is only i", so to avoid confusion, it is customary in the case of mul= 
tiple threads to use the actual linear pitch of the thread or helix and designate it lead. So in this case, we 
have i" lead. 

104. However elaborately a screw is drawn, the pitch should be specified always. If it be irregu- 
lar in any w^ay, that is, if it be multiple threaded, or left handed, it should be so designated. 

CONVENTIONAL THREADED HOLES FIG. 10 

105. Here we have various ways of showing threaded holes, so as to save time and avoid the 
confusion of lines. A and D are not much used. Note the angle of 120° used to show the drill point. 
Note also that the depth of the hole is not measured to the drill point, but to the corner. If two parts 
are threaded together and then cut with a sectioning plane, it is necessary to draw the thread. See Fig. 
8, B. 

COMMON FORMS OF BOLTS FIG. 10 

106. Through Bolts are always used where possible, in order to reduce expense. In some cases, 
however, as on a steam engine cyhnder end, it may not be possible to get at the head of a bolt on the back 
of the cyhnder flange. In such a case, stud bolts would be used for holding on the cylinder head. A tap 
bolt is sometimes used for the same purpose, if the cylinder head will not be removed very often. Where 
a bolt of this kind is frequently turned in and out of a hole tapped in cast iron, the thread on the hole 
is quickly destroyed. Such a bolt is therefore most suitable for a permanent connection. ^ 



38 

107. The anchor bolt for concrete is to be placed while the concrete is yet plastic. The one for 
stone is driven into a hole that flares slightly at the bottom, the wedge spreading the end to fit it. 

108. If one view of a bolt head or nut is shown and then only for pictorial purposes, the hexagonal 
form should show three faces and the square form should show one face. There can be no question then 
as to which is intended. If one view only is shown in a working drawing, show two faces for the hexagonal 
form and one for the square. This permits dimensioning the distance between flats, a measurement the 
workman will need, if the faces are milled. 

109. The needed dimensions on the stud bolt are shown. See Table 4 for sizes. Nut and bolt 
dimensions follow no universal standard. They are most frequently made by the U. S. standard, the 
proportions for which are given in the drawing and in Table 1. These values apply to both square and 
hexagonal forms. Note the appearance of the chamfer on head and nut. Its angle is 45°. Note also 
that the bolt points are either rounded or beveled at 45° and that the thread lines do not run to the extreme 
point. The length of a bolt is measured from under its head to its extreme point. The diameter and 
length of thread are also essential dimensions. Pitch of thread need not be specified on a through bolt, 
but it is necessary on a tap or stud bolt, so as to agree with the tapped hole into which it will go. 

1 10. The table on Standard Bolts and Nuts is the Franklin Institute or Sellers' Standard and is for 

rough bolts and nuts. Referring to the dimensions given in Table 1, 

r = l^D+J" for head and nut. Thickness of head = f Thickness of nut = D. 
For finished bolts and nuts, 

F = liD+j^". Thickness of head equals thickness of nut = D — 33^". 

The U. S. Government uses the rough standard for both rough and finished bolts and nuts so the 
same wrenches may be used on either. 

The Manufacturers' Standard follows these dimensions for bolts. 

F = liD for heads. Thickness of head = D- j^^" for sizes i" to ^", is W' for f" and = D-|" for 
sizes l" to 2". 

The dimensions of nuts will vary according to the manufacturer. 



39 

SCREWS AND SCREW HEADS FIQ. 10 

1 11. The terms "bolt" and "screw" are used iiiterchaiageably by so many people that it is diflS.- 
cult to distinguish between them. We may classify them roughly by saj^ing that a bolt is a screw and a 
nut, while a screw is simph^ the one piece. 

The ways of representmg and dmiensioning the commoner kinds of screws are shown here. For 
the Collar, Knurled, Fillister and Button head screws, the length is measured from under the head to 
extreme point. For the Flat head, however, it is the overall length which is taken. Alost bolts and screws 
pull the parts they comiect together. A Set Screw acts by forcing them apart. For this reason it has 
to be case hardened, at least on the point. 

1 12. ]Man5'' screws are turned out of bar stock and then- diameters run on the common fractional 
sizes. Thej' are called milled or cap screws. Thej' are frequently case hardened. The dimensions used 
bj' the different manufactiirers vary sUghtly and the ones given in the tables are principally those of the 
Worcester ^lachine Screw Co. 

Diameters of the Square and Hexagon head screws range from j" to li". See Table 2. 

1 13. Diameters of Flat, Round and Oval Fillister head screws range from |" to 1". As used, the 
entire head may project or it may be sunk partly into the metal by counterboring the hole. See Table 3. 

1 14. Diameters of Flat and Oval Countersunk head screws and Button head screws range from 
I" to I". A common angle for the countersunk head is 70°. See Table 3. 

115. Diameters of Collar head screws range from J" to |". It is reaU}^ a screw with a fixed washer 
attached. It is used where the screw must be frequently removed, as for instance, on the jaws of a 
milling machine vise. Heads are usually case hardened. See Table 4. 

1 16. Diameters of Set Screws range from l" to IJ''- There are several kinds of points and heads 
as shown in the table. Regular set screws have cup or oval points, have square heads but shghtlj^ greater 
than that of the body and are case hardened. See Table 2. 

117. Machine Screws. Small screws are made from wii'e by upsetting one end for the head. 
Their diameters are therefore the wu-e sizes and are specified by the numbers of the screw gage. These 



40 

are designated machine screws. See Machine Screw Gage and the A. S. M. E. standard for machine 
screws in Table 5. Commercial sizes of brass and iron Flat, Round and FilUster head screws have these 
diameters by gage. Numbers 2, 3, 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 24, 30. Lengths from ^" to f " vary 
by 16ths, from f" to U" by 8ths, and from U" to 3" by 4ths. 

1 18. Punched washers are designated by the largest size of bolt with which they can be used, and 
then- thickness by Birm. Wire Gage. See Table 9. For sizes of Cast Washers, see Table 10. 

119. A lag or coach screw is a large, wood screw made to be driven by a wrench instead of a screw- 
driver. Necessary dimensions are as shown. 

These screws have square or hexagonal heads. From I" to f ", the diameters advance by lOths of 
an inch and from f" to 1" by 8ths. The lengths from U" to 6" advance by half inches and from 6" to 
12" by inches. 

120. The included angle for flat head wood screws is 82°. The diameter of the head is approxi- 
mately 1.9 times the diameter of the body of the screw. The range of commercial lengths is as follows: 
Up to 1" by 8ths, from 1" to 3" by 4ths, and from 3" to 5" by half inches. See Wood Screw Gage in 

Table 5. 

RIVET FASTENINGS FIG. 10 

121. There is a great variety of rivet forms and only the three common ones are shown. Diam- 
eter and length as indicated designate the size. Note how the length of the countersunk head type is 
measured. Proportions of heads vary, but are approximately as shown in the illustration. 

Button and Countersunk heads are used in structural work, Pan heads for boilers and Countersunk 
heads for hull plating. See also the chapter on Structural Drawing and Table 14. 

KEY FASTENINGS FIG. 10 

122. There are three types of keys in common use as follows: A Taper key, such as is used for 
fastening a pulley to a shaft so it cannot rotate nor slide on the shaft, fits on all sides and is driven in tight. 



41 

If its small end is not accessible for driving out, then a Gib Head key is used like the one shown in the 
drawing. The section under the head is commonly square. This dimension and the length under the 
head are sufficient to designate it. If it is not square, give width X thickness X length. See Table 7. 

123. The following commercial sizes are those of keys made by the Standard Gauge Steel Co. 
These keys are square at the large end and have a taper of J" in 12". Size of large end varies from I" 
to 3" by 16ths of an inch. Lengths from V to 24" vary by half inches. See Table 6. 

124. The second type of key fits on the sides and prevents relative rotation but not sliding endwise. 
These keys are commonly square and are dimensioned as in the drawing. The Whitney or Woodruff key 
belongs to this class. Its size is designated by manufacturer's number, but the length and width are often 
given so as to show the size of cutter required. See Table 1 . 

125. The third form of key is the Feather key. This is usually rigidly attached to the shaft or to 
the hub, so as to permit shding of the parts endwise without its loosening. These keys are generally of 
greater depth than the other kinds. The depth or thickness of a key is its radial dimension as it Ues on 
the shaft. 

126. A Key is subjected to shearing on a longitudinal section. A Cotter is a similar fastening 
which is subjected to shear on a transverse section. Cotters are often called keys especially on the con- 
necting rod of an engine where they are used to draw up the boxes. A cotter is tapered and is driven 
tight to draw the connected parts together. It may hold by friction or be held by a set screw. In specify- 
ing, use the dimensions shown in the drawing. 

127. A spring cotter or spht pin is not used for drawing parts together, but to prevent a puUey 
or nut from coming off a shaft endwise. After pushing the pin through its hole, the ends are spread thus 
preventing its working out. Diameter at the neck and length under head to extreme point are the 
necessary dimensions. Diameters from ^" to ^" vary by 64ths of an inch, from I" to J" by 16ths of an 
inch and from ^" to %" by 8ths of an inch. See Table 10. 

128. Note the dimensions and specifications for the coiled spring in Fig. 9. 



SrffAIQHT COUPLINq F!£DUCIN(^ CO(//=: 



Y 8/^ANCH 



^5° ELBOmf 



""vV^v'vVW 




BEADED F/rr/NG 



Flan(S£:o F/t tinq 




Fife 

FiTTINQ 




For Rapid Conventional Si^£TCHing 



Elboiv 









-^ 



This is a Plan View 



Cap Ofi Pi.</^ 






Y =^k h© 



l-kXl'x^TEE 

Fig. II 




-Pipe. 



— C/ross 




# 



\ 



'tZ/VfON 



-Y BfiA/</cH 



r-r^S ELBoyV 



43 

PIPE CONNECTIONS FIG. 11 

129. Ordinary Standard wi-ought iron pipe is designated by its nominal inside diameter. Thus a 
12" pipe is just 12" in internal diameter, while a J" pipe is .269" in internal diameter. See Table 1 1 for 
properties. 

Extra and Double Extra pipe are of the same outside diameter as Standard, so then- inside diam- 
eters have no significance. The thread for a pipe is special, standard for the various sizes and is never 
specified in a di'awing. See Section 100. If a hole is tapped for pipe the specification is, 2" Pipe Tap, 
for instance. 

130. The term fittings apphes primarily to the parts used for connecting the different lengths of 
pipe. Valves are not considered fittings. Sketches of the various fittings and their names are given in 
Fig. II. Their use is indicated in the sketch showing a pipe "layout." 

The size of a fitting or valve is given as that of the largest piece of pipe which can be screwed into it. 

A straight coupling connects two pipes of the same diameter, while a reducing coupling connects 
two pipes of different diameters. ^Nlany fittings are threaded right and left to permit of making connec- 
tions on a circuit of piping. If the connection must be sometimes broken, it is better to use unions to 
complete the circuit. 

Elbows and bends pro^dde for changes in direction, wMe Tees, Crosses and Y branches pro^'ide 
for branches and for changes of direction. 

On a fitting with side outlets the main part is called the run. The fitting is always specified by 
giving first the dimensions of the run and then those of the outlets. In Fig. 1 1 , Y, is shown how to desig- 
nate a Tee. 

A flange union is used where the joint must be tight and the pressm-es are high, as on steam piping. 
Screw unions are used on the smaller sizes of pipe, especially for water pipe. 

Gate, Globe and Check Valves are shown ui Figs. 12 and 13. Where the fluid is a hquid, the gate 
valve is commonly used. For small steam pipes and where steam must be throttled, the globe or angle 
valve is generally used. On high pressure, large size steam pipe fines, gate valves appear to be preferred. 




Fig. 12 



Isometric Pipe Drawing 



Fig. 13 



45 



though both kinds are used. A common Globe valve is used for a straight run of 
is used at the junction of two pipes forming an L, and a Cross valve is used at the 
forming a T. In these valves, the disc which closes the opening is moved parallel 
to the axis of the opening, while in the Gate valve, the disc is moved perpendicu- 
lar to the axis. 

131. The conventional drawing of a pipe "layout" shown in Fig. II may 
be further simpUfied by using single lines for the pipe and fittings. A riser is a 
vertical section of pipe. In a sketch of this kind, give distances to center lines of 
pipe, the size of pipe, name and size of each fitting, kind and size of each valve, 
cock, drip, lubricator or other apparatus on the line. Where it is necessary to 
locate valves or fittings exactly, give the dimension along the pipe to the center of 
the fitting. For an inclined pipe, give the vertical rise in a given horizontal dis- 
tance. Fig. 13 shows an Isometric sketch of a pipe system. This is made as di- 
rected in Sections 259 to 262. Draw first, the center lines of the pipes, then locate 
on these the center of each fitting as required. Draw outhnes of the pipes and 
sketch in the ends of a fitting first, filling in the body afterward and building it up 
as usual in making an axometric sketch. In a sketch of this kind, it is not advisa- 
ble to attempt to follow minute details and dimensions too closely. The propor- 
tions of fittings shown in Fig. 12 represent average commercial forms which vary 
considerably. Note that the diameter of the body of the fitting is approximately 
the mean of the pipe and the bead diameters. Note conventional designation of 
a valve at A. 

TAPERED PARTS 

132. Tapered arms and hubs of pulleys, sheaves, gears and other wheels are 
designed for a certain amount of total taper per foot. This taper is usually given 
on a drawing, however, by specifying the dimensions at the small and large ends. 



pipe, an Angle valve 

junction of two pipes 

U.S. Stand, for Plate. 



J 
5 
7 
9 



/ p. J .zms 

m///////////////M 



m 



m 



.25 

.21875 
.1875 
.15625 




.09375 



16 VMMM//M^77P7m .0625 

18 v//m/mm///mMa .05 

20 ^.m,m^^ .0375 

22 ^—^--i- .03125 

14 .025 

28 .oise^s 

Fig. 14 

See Pulley, Fig. 9. 



46 



0000 



Birmingham 



000 








.340 
10 



Gage 
I 



.300 



284 



.iOZI -i^oo 



II 12 13 



14 



15 
® 



16 

® 



.134 

Fig. 



.120 .103 .095 .083 .072 .065 

15 



Tapering arms of levers and handles are designated in the same way. See Binder Handle, Fig. 9. 
Tapered parts that fit tapered openings are usually specified by giving the dimension at one end 
and the taper in inches per foot. See Gib Head Key and Cotter in Fig. 10. 

Taper of centers, tool shanks and pins is 
designated by giving the diameter of the small end 
and the taper in inches per foot as measured on the 
diameter. See Fig. 8, B. 

A tapered hole is drilled, turned or bored and 
reamed. The drill diameter, taper in inches per 
foot and diameter at the large end are to be given. 
If some one of the numerous standard taper reamers 
is used, it should be specified. Thus, No. 3 Morse 
Taper. Brown & Sharpe tapers are commonly used 
in the spindles of milling machines and the Morse taper for the spindles of drills and lathes. The Jarno 
taper of /o" per foot and other special dimensions is being used by some manufacturers. See Table 13 
for the B. & S. and Morse tapers. 

On account of the confusion regarding the measurement of tapers, many draftsmen prefer to make 
a supplementary construction showing just how the taper is measured. 

GAGES 

133. So many gages have come into use for measuring the various kinds of wire and sheet metals 
that it requires an expert to keep them properly differentiated. A few of those most useful to the drafts- 
man are given. In order that the sizes may become associated with the numbers, a limited number of 
plate and wire sections have been given in their actual sizes or as near them as is possible with a printed 
figure. It should be remembered that the Birmingham Wire Gage is the Stubs' Iron Wire Gage and not 
the same as the Stubs' Steel Wire Gage. The Twist Drill and Steel Wire Gage is for twist drills and drill 
rods. It nmst not be confounded with the many other steel wire gages. See Figs. 14 and 15 and Table 5. 



47 




WHOLE Depth 



Fig. 16 




CHAPTER IV 

TOOTHED QEARINQ 

^ fioDENouM UNg^ 134^ jf ^-^o cylinders revolving on parallel shafts are pressed 

together, one will drive the other by friction, if the resistance of the 
driven cylinder to turning is not too great. With great resistance, 
slipping will occur and to avoid this, projections may be put on each 
cylinder with hollows between to accommodate the projections of the 
other. If these projections and hollows are properly shaped, the result 
is a pair of toothed gears. The original cylinders are called pitch 
cylinders. In Fig. 16, the pitch line or pitch circle is the projection of 
the pitch cylinder. The part of the tooth outside this line is the adden= 
dum and the part inside, the dedendum. The length of pitch line between centers of two adjacent teeth 
measured in inches is called the circular pitch. The tooth width is measured in the same way on the pitch 
line, as is also the space width. Note also the fillet and the clearance. The working depth line shows how 
near the tops of teeth of a mating gear approach to the bottom of the space. Face of a tooth is the work- 
ing surface outside the pitch line and the flank is the working surface inside. 

135. Ordinary gears have a whole number of equal teeth and of equal spaces. If the number of 
teeth on a gear be divided by the diameter of the pitch circle in inches, the quotient is a number called 
the diametral pitch. Thus in the Spur gear Fig. 18, the number of teeth, 16, divided by 2, the number of 
inches in the diameter of the pitch circle, gives 8, the number of the diametral pitch. This diametral 
pitch is the one commonly used in designating the gear. It is useful to remember that Circular Pitch 
X Diametral Pitch = ''■. 

136. The circular pitch system of designing gears still survives in the case of heavy power trans- 
mission gears with cast teeth. There is no argument in its favor except that it saves the scrapping of 
large numbers of stock patterns and tooth forms constructed on that system. Of course, any system of 



48 

gears tends to perpetuate itself, because generally only one gear of a pair breaks at a time and the owner 
must replace it with another of the same system or else throw away the remaining good gear. The dia- 
metral pitch system will doubtless displace the other in time. The circular pitches in most common use 
are as follows : From f " to 2h" by 8ths, from 2i" to 4" by 4ths, and from 4" to 6" by halves. 

137. For cut teeth the proportions are as follows. 

Tooth Width = Space Width = i Circular Pitch. Addendum Length = p^^metral Pitch 

Addendum Length, ^, Tooth Width 
Clearance = g ^—' or Clearance = ^q 

Dedendum = Addendum + Clearance Fillet Radius = Clearance. 

In the case of Cast teeth not machined, the space width exceeds the tooth width by an amount 
called the back=lash. This provides for running in spite of irregularities of the teeth. 
Fig. 17 shows the actual sizes of gear teeth of the common diametral pitches. 

138. Tooth outUnes are single curved or Involute, as in the Worm Gear, Fig. 18, and Fig. 17 
and double curved or Cycloidal as in Fig. 16. 

139. The dhnensions needed on the drawing of any gear are as follows. Dimensions for the 
pattern-maker, if a casting is used; dimensions to enable the machinist to turn up the blank, as the uncut 
gear is called, and dimensions necessary for selecting the cutter and setting up the work in the machine 
where the teeth are cut. Only those dimensions and specifications relating directly to the teeth will be 
mentioned in considering the following gears. 

SPUR GEARS FIG. 18 

140. Dimensions necessary for teeth are thickness and outside diameter of blank, number, kind 
and pitch of teeth. 



Actual Sizes of Gear Teeth 



l^BLE OF D/AMCTfiAL P/TCHES ANO CIRCULAR P/TCH EQUIVALENTS 



Oiam.Pi. 


Or. Pi 


DiarnPi. 


Or. Pi. 


Diam.Pi. 


dr. Pi. 


Oiam.Pi. 


Cir.Pi. 


Z 


1.571- 


5 


.628- 


la 


.zez- 


26 


.izr 


2>^ 


I.33G- 


6 


.S24-- 


14 


.ZZ4- 


aa 


.112- 


2yz 


I.ZST 


7 


-449- 


16 


.196- 


30 


.105- 


2M 


I.I4-Z- 


8, 


.J93- 


18 


.175- 


32 


.038- 


3 


L(M-7- 


9 


.343- 


20 


757- 


36 


.087- 


syi 


.838- 


)0 ' 


.314- 


22 


.143- 


40 


.079- 


4- 


.785- 


II 


.286- 


24 


.131- 


48 


.065- 




f<P^22 







Fig 17 



50 

RACK FIG. 18 

141. A rack is essentially a Spur Gear with an infinite diameter. Give its length and width, the 
kind and pitch of teeth. 

BEVEL GEARS FIG. 18 

142. In bevel gears the pitch surfaces are cones. In the drawing they are shown as isosceles 
triangles DAB and DBG. The pitch circle on the pitch cone, used for calculations is AB for the small 
gear and BG for the large, that is, the largest in each. 

Gonsidering now the small gear only, note that a tooth tapers from its large end as at UAT toward 
the vertex, D, of the pitch cone. The dimensions of the large end of the tooth are the ones used in cal- 
culations and it should be observed that this large end lies in the surface of a secondary cone whose ele- 
ments are perpendicular to those of the pitch cone. This cone VAB is called the back cone. The pitch 
diameter of the small gear is its largest pitch diameter i. e. 2". The number of teeth is 20 and the dia- 
metral pitch is therefore number 10. The tooth addendum length xAT is ^o" ^i^d the dedendum length 
AU is s'V'- The various angles and increments may be computed by trigonometry, or by means of Bevel 
Gear Tables. 

Thus, having the pitch radii of the two gears, BZ and DZ, the center angle of 29°. 75 can be found. 

AD can be found as the hypothenuse of the triangle AZD. From AT and AD, find by trigonometry the 

angle ADT, which added to the center angle gives 32°. 58. The complement of this angle, 57°. 42 is the 

face angle. From UA and AD determine angle ADU, which subtracted from the center angle gives 

26°. 55 for the cutting angle. The angle VAZ is called the angle of the edge and it is equal to the center 

angle. The outside diameter equals pitch diameter AB, + 2 AT Gos. 29°. 75. The cutter is selected for 

AV. 
10 pitch and for a number of teeth equal to the number of teeth of the gear, 20, multiplied by -^ 

To size for teeth, the machinist will need the outside diameter, the backing, angle of the edge, face 
angle, face of blank. For cutting teeth, he will need the number, kind and pitch of teeth, the number of 
teeth which determines the cutter and the cutting angle. 



Srur Gear Rack 

,0/^£~C./.- f ALL OyS^/Ji-ZSV/vyOL. OAf£-C./.-f ALL 0l^£^-/2Pl-STD.CyCL. 



^Nd3A. 



Bei/el Gears 
One Each —Mach. -St. 



E - Shaft An^lc 
F- Centek Angle 
H- FACE Anqle 
J - Angle of edge 
L - Cutting Angle 

M- BACKING 

D 

Pitch Cones 

ABD -BCD 



60.25 
26?S2 
60°25 
51?05 

'/e 




52 

WORM GEARING FIG. 18 

143. If the teeth on a spur gear are turned slightly so their angle agrees with the thread angle of 
a screw having the same circular or linear pitch, the two will work together properly and constitute a 
simple form of Worm Gearing. The thread section of the worm is made like a rack tooth and the relative 
action of the teeth can be best understood by thinking of the worm as a rack. 

If a more extended contact between the thread of the worm and the teeth of the gear is desired, 
a milling cutter is made which is almost an exact duplicate of the worm. This is run with the worm gear 
and shapes its teeth. Such a cutter is called a hob and when one is used, the teeth of the gear are often 
first roughed out with a rotary cutter set at an angle to agree with the thread angle. This operation is 
called gashing. 

AU the dimensions relating to the tooth are calculated, but the outside diameter of the gear may be 
measured from the pencil drawing. Dimensions should be given in thousandths of an inch. 

Dimensions for Worm are, length, outside diameter, root diameter, lead and kind of meshing tooth. 
If more than one thread is used it should be specified. 

Dimensions for Worm Gear are, outside diameter, width and bevel of blank; throat diameter, 
radius and width of groove; number, kind and circular pitch of teeth; tooth angle should be given if the 
gear is gashed. Tooth dimensions are based on the fractional diametral pitch corresponding to the given 

circular pitch and in the usual way. The addendum length in these teeth is equal to j- or .07958". 

SPIRAL GEARS FIG. 18 

144. If instead of a single thread on the worm used with the worm gear, a large number of threads 
had been used, then the lead would have been greatly increased and the angle between the thread and the 
axis of the worm as shown in the projection would have been greatly decreased. The threads on the worm 
would then appear more like teeth than threads. The tooth angle on the worm gear would have 
changed accordingly and the result would be two similar gears in which the teeth were portions of threads 
of very large lead. Such gears are called Spiral Gears. 



53 

In the case illustrated by the drawing, the center distance between shafts is 4ff ", the ratio of num- 
bers of teeth on the gears is -f, the shaft diameters are H" and cutters to be used in cutting the teeth are 
6 pitch. The necessary dimensions are shown in the drawing. Note that the relation between pitch 
diameter, pitch and mmiber of teeth is not as in other gears. 

145. In laying out a pair of spiral gears connecting two shafts at right angles, but which are not 
in the same plane, there TvdU usually be some fixed conditions such as center distance of shafts, speed ratio 
of the gears, minimimi or maximum diameters of the gears and a limited number of available tooth cutters. 
It will be necessary to determine first the relation of these various conditions by a consideration of the pair 
of completed gears shown in Fig. 18. 

Let S = center distance of shafts. 

Wg= angular velocity of gear. Rg = radius of gear. 

Wp = angular velocity of pinion. Rp = radius of pinion. 

Vg = pitch line velocity of gear. Tg = no. teeth on gear. 

Vp = pitch line velocity of pinion. Tp = no. teeth on pinion. 

Yg = no. teeth determining cutter for gear. Z = diametral pitch of cutters. 

Yp = no. teeth determining cutter for pinion. ^ = helix angle for teeth of pinion. 

Referring to Fig. 18, right hand view, imagine the pitch surfaces of the pinion and gear to be pieces 
of paper wrapped on the pitch cylinders. Cut the pinion paper on the back side along an element and the 
gear paper on the front side along an element. Considering the two papers to be held tightly together 
at the point of contact of the two gears, let the papers flatten out into a single plane which will be tangent 
to the two pitch surfaces at their point of contact. The appearance of these two papers will be as shown 
in Fig. 19. 

The rectangle X-B is the developed pitch surface of the gear, the obhque lines being the center 
lines of its teeth. The rectangle C-D is the corresponding development for the pinion. The tooth center 
lines being helixes, become straight lines in the development. Line E-F is the development of part of a 
helix passing through 0, the point of contact of the pitch surfaces. This helix is normal or perpendicular 



54 

to the center lines of teeth on the gear and a corresponding helix, HK, on the pitch surface of the pinion, 
coincides with E-F when that surface is developed. E-F is therefore perpendicular to the developed center 
lines of the teeth. 

The number of spaces on the line A-B equals the number of teeth on the gear and the spaces on the 
line C-D equal the number of teeth on the pinion. From the figure, it is seen that the number of spaces 
on E-F and A-B are equal, while the number on H-K and C-D are also equal. 

When the front surface of the pinion moves to the right one tooth, or one circular pitch, of the pinion, 
its component motion along E-F is equal to one normal pitch. This motion causes the back side of the 
gear to move downward a distance equal to one tooth or one circular pitch of the gear and its component 
motion along E-F is equal to One normal pitch. 

Therefore 

V„ Circular Pitch of Gear 

— s = = tang 6 

V„ Circular Pitch of Pinion 



p 



V„ 



Speed Ratio =^-=^= ^^^tang 6 and „^^« = 5? 
Wp Vp Rg ^ Wptange R 



g 



Rp 



By composition, ^ -=-d ,^-p > but Rp-j-Rg =S 

Wg+ Wp tang e Rp+Rg 

S 2S 

andRi, = or Diameter of Pinion = 2R„ = . . . • (1) 

W W 

1-l-^tange 1+^tange 

Wg Wg 

In cutting the teeth, the work is fed in the direction perpendicular to E-F and the width of cut will 

be one half the normal pitch. The diametral pitch of such a cutter equals-^r^^ , p., , = Z, 



55 



or the Normal Pitch =y-. Tp = the number of teeth on the pinion. 



Then HK = TpX Normal Pitch ^TpXy 



TT 



"'^K-zl^. • • <'' 

Combinmg equations (1) and (2), 2Rp - -—i^= — • • • • (3) 

1+— E tang e 

146. Suppose the following quantities are given: 

The center distance of shafts— S. The speed ratio——-?. The diametral pitch of available cut- 

ters — Z. 

The angle & should be about 45° for best efficiency, but may be as smaU as 12° for hght work with 
the gears running in an oU bath. The best range is from 20° to 45°. 

The angle (9 must also be one that will permit cutting the teeth on the millmg machine. 

The minimum diameter for the pinion will be determined by the size of its shaft and key. 

Tp must be a whole number and we see from Fig. 19 that if Tp is integral, Tg will be also. 

Inspection of equation (3) shows that if S, Z, and-— ^ are fixed, then values for Q within its allow- 

able Umits must be tried until one is found which when substituted in (3) will give a whole number for 
Tp and a satisfactory value for Rp. Inspection of Fig. 19 will suggest various graphical solutions. The 
numerical solution is very tedious even when expedited by the slide-rule. Several solutions are usually 



56 



SpjnAL Gears 

A 



possible, but the selected conditions may be such as to give no solution. In the latter case, the con- 
struction of a figure like Fig. 19 will generally show where the difficulty lies. 

The numerical values for the diameters and tooth angles as given in Fig. 
18 are quoted from, "Worm and Spiral Gearing," by F. A. Halsey, because they 
were obtained with great accuracy on a calculating machine. 

Note that the tooth angle is the angle which the tooth helix makes with 
the axis of the pitch cylinder. It is therefore the complement of the angle 
commonly given as the helix angle, namely, the angle which the helix makes 
with the plane of the end of the cylinder. The tooth angle as specified in Fig. 18 
is more convenient for the workman, as it is the amount necessary to set over the 
head of the milling machine for cutting the teeth. 

147. It remains to determine the number of teeth for which the cutter 
is selected. It will not be the same for the pinion and gear. For the pinion, 
it depends on the radius of curvature of the normal helix of the pinion, and for 
the gear, on the radius of curvature of the normal helix of the gear. 




It can be proved easily by geometry, that Yp = 
The student should verify the results given in Fig. 18. 



^^ and Y. 



Sin^^ 



Cos^e 



O£i^£L0P£O Pitch Surfaccs 



Fig. 19 



148. The pitch diameter is always given on a gear although it may be 
of no use to the machinist. It is necessary, however, in determining the center 
distance between the connected shafts, or for checking and computing parts of 
the gear. For gears with cast teeth, it is needed by the pattern-maker in laying out and setting teeth, 
when wood patterns are used. 

The machinist, in cutting teeth, needs many dimensions not given, such as total depth of cut, ad- 
dendum length, etc., but these are seldom put on a drawing of the nature here described. 



57 



149. Spur gears are used to connect parallel shafts, Bevel gears to connect shafts not parallel, 

but in the same plane. Spiral gears are used to connect shafts not in the same plane and at any angle, 

Worm gearing to connect shafts not in the same plane, but at 90° angle. Bevel gears of the same size 

coimecting shafts at 90° are called Mitre Gears. Bevel gears connecting shafts not at 90° are often called 

Angle Gears. 

T , ^, t .J. .' e j.i_ • 1 turns per minute of the driver , 

In each case the velocity ratio of the parr equals, -. t—, r~- equals 

turns per minute of the driven 

In the case of worm gearing, a thi-ead would be counted as one tooth. 



number of teeth on the driven 
number of teeth on the driver 



REFERENCE BOOKS ON GEARING 



150. American iSIachinist Gear Book — C. H. Logue. Essentials of Gearing— G. C. Anthony. 

Formulas in Gearing — Brown & Sharpe -Nlfg. Co. A Treatise on Gear Wheels — G. B. Grant. 

Practical Treatise on Gearmg — Brown & Sharpe Alfg. Co. Worm and Spu-al Gearing — F. A. Halsey. 

Essential Data of Bevel Gearing — ^E. J. Frost. Gear Cutting iNIachinery — R. E. Flanders. 

CHAPTER V 

STRUCTURAL DRAWING 

151. Shop drawings of structural details are similar to those used for machine construction, but 
there are some differences which will be noticed in this chapter. Many of these notes are based on the 
practice of the American Bridge Company, and the illustrations are in Figs. 20, 21 and 22. 

There are two common methods of making shop drawings. By the first, the drawing is made so 
complete that templets can be laid out separately on the bench for each individual piece. The Plate 
Girder, Fig. 20 is an illustration of this method. 



58 

152. By the second method, the drawings give only sufficient dimensions to determine the position 
and length of the main and secondary members, leaving the details to be worked out by the templet maker 
on the laying out floor. The Roof Truss, Fig. 21, is an illustration of this method. In this case, the 
working or gage lines, U-Y, V-X, X-Y, etc., would be laid out on the floor with chalk lines actual size, 
for the entire truss. These lines give the lengths and bevels for the different members. For instance the 
size, shape and rivet spacing for the gusset plate at the joint X can be drawn on the cardboard commonly 
used for such a templet by reference to the lines meeting at X. The templet for the angle V-X would be 
laid out in a similar manner by laying it beside the line on the floor and marking off its length and the 
points for rivets. Such a templet would be made of a long, thin strip of pine one edge of which would be 
flush with the intersection of outside surfaces of the legs of the angle. The rivet center line or gage line 
would then be marked in its proper position on the strip, the rivet centers located and holes about ^" 
in diameter bored for each rivet. An angle having been cut to the correct length, the templet would be 
clamped in position on the outside of the leg to be punched. The workman then takes a prick punch which 
fits the holes already bored in the wood and prick punches on the angle the center of each rivet. The 
angle then goes to the machine to have the rivet holes punched. The punch used in this machine has a 
feeler on the end which, catching the prick punch mark, centers the angle relative to the punch so that the 
resultant hole is properly placed and with a minimum expenditure of time. Such a punch is shown in 
an inverted position at K, Fig. 34. 

153. Though it is permissible to omit the dimensions for locating rivets in a drawing of this kind 
when the connected parts are shown in place together, such dimensions should never be omitted if the 
connection is to be made in the field. Thus, in the Roof Truss, the rivet locations are omitted for the 
gussets, but are given at U for the rivets connecting the end of the truss to the top of the column that 
supports it. 

154. While practice regarding the application of these two methods is not uniform, columns, plate 
girders, heavy lattice girders in buildings and chords, floor beams and stringers in highway bridges are 



/^/yets — -g 



Opc/7 Ho/grS — 7g (JnfcrSJ nofccf. 



Mi&AMiiiU 


/ 4«4''l'-*' 


3f3i 


3 


s&^'^z-q' zziiiii flea'. 2-0' ?j'z5iF'3y4' 




z 


3 2233 


r 








1 










i 






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T 




1 






































,"rs- ^,r 




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-k 


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=^ 


=-si.-^ 


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=3i„5^=^.=i^=i= 




■=-^.^:^^^^^- ^^r^^^^^r:r-^^r^:[^:ir^^r^=^r~. 






=^^:^^r=^~E-3 




planch on hofiom to ^ 

7x/§ s/offcd Ho/c^ for Expansion End. 
1^ dia Holes for Eixed End. 



60 Ft. Deck Plate Girder 



Fig. 20 



60 

generally laid out by the first method. Roof trusses, light lattice girders and complicated work such as 
towers, domes, etc., are laid out by the second method. 

155. The common scales for details are J" and 1" to the foot, but for large plate and lattice 
girders, \" and f" are used. 

156. Members are shown as nearly as possible in the positions they occupy in the structure, the 
horizontal members horizontal and the vertical members vertical. If, because of lack of space, an incUned 
or vertical member is shown horizontal, it should have its lower end at the left. 

The top view is placed above the elevation. The bottom view is placed below the elevation. The 
bottom view is a horizontal sectional view as seen from above. 

157. Cut parts are cross hatched if large enough, otherwise they are blackened. If blackened, 
open holes for field comiections are left white. See Fig. 10 and Fig. 20. 

158. Center hues or working lines generally coincide with the rivet gage lines. In Fig. 21 these 
would be U-Y, U-X, V-X and X-Y. Some draftsmen use the line of intersection of the backs of legs of 
an angle for a center line. A few use the line through the center of gravity of the section. Give the dis- 
tance from the gage line to a finished edge. 

159. The bevel or inclination of one member to another is designated by a right triangle one of 
whose legs is usually 12" long. The principal use of bevels is in laying out gussets. See Figs. 21 and 22. 

160. Heads of shop rivets are shown in the view where they appear as circles and seldom otherwise 
except for indicating clearance as in the case of the clip angle, Fig. 22. 

161. Open holes for field connections are always blackened except as noted in Section 157. 

162. Conventional Rivet Signs, Fig. 10, enable the draftsman to avoid covering his drawing with 
printed notes regarding the heads and points of rivets. They also permit a great saving of time. 

163. The dimensions of rivets commonly used on structural work are given in Table 14. In naval 
construction the diameters range from J" to IJ". 



61 

164. The location of rivet gage lines for the various sizes and shapes of sections has been partially 
standardized and these are given in Table 14. In the case of a line of rivets in a plate, the center line should 
be located from the finished edge if there be one. 

165. To provide space for the riveter die, a certain amount of clearance between adjacent rivet 
heads is necessary. These clearances for different sizes of rivets are given in Table 14. 

166. It has been found necessary to limit the distance between rivet holes and the distance from 
a hole to the edge of a plate, for if it is too smaU, there is danger of fracturing the plate when punching. 
Thus, the minimum distance between centers of holes is taken equal to three diameters and from the edge 
of a plate to the center of a rivet as one and one-half diameters of the rivet. These distances are usually 
shghtly exceeded in practice. Those commonly used are given in Table 14. 

167. In a single row of rivets, the distance between two consecutive rivets is termed the pitch. 
See for example the end cover plate on the Plate Girder, Fig. 20. In a double row of rivets, the distance 
between two consecutive rivets in alternate rows measured parallel to the gage liaes is termed the pitch. 
This is illustrated in the top flange of the Plate Girder, Fig. 20. 

168. In a long row of rivets, it is customary to space them equally or to arrange them in groups 
of equal spaces. "WTien so arranged, the spaces are dimensioned in groups instead of singly, thus, 5 @ 
y= I'-Z" means that there are five spaces three inches long and that they total a length of one foot and 
three inches. See Plate Girder, Fig. 20. 

In case of a double row of staggered rivets, they are often specified as follows. 7 alt. @ 4" = 2'-4". 

169. Sti-uctm-al steel shapes are designated as follows: 

For an I Beam give — depth of web X weight per foot X length. 
For a Channel give — depth of web X weight per foot X length. 
For an H Section — give depth of web X weight per foot X length. 
For an Angle give — length of leg X length of leg X thickness X length. 



Material for One: Truss 



NUMQER 
ReguifiEO 


Mark 


De^cfiiption 


Lensth 


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T.C. 


11 Si'^f^ ^ 


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Roof Truss 



Rivets - 4 



Open Holes — f^ 

Sfd. Qa^es unless noied. 

Paint- I Coat -Black. 




Fig. 21 



63 



For a Z Bar give — depth of web X length of leg X thickness X length. 

For a T Bar give — width of flange X depth of bar X weight per foot X length. See Fig. 10. 



170. Gusset plates are often designated by their thickness only as are those of the Roof Truss, 
Fig. 21. Their size is usually given more completeh' by the width m inches X thickness X length in feet 
and mches of a rectangular plate from which each could be cut. The following are examples. 15" X i" 

X 0'-9" 7" X f" X I'-O" U" X i" X l'-2". The length is commonly taken as the dimension 

along the principal member to which the gusset is connected. 

171. Rectangular plates such as web plates and fillers are designated in the same way as gussets 
except that the longest dunension is usually taken as the length. See Plate Gu-der. Fig. 20. 

172. Lattice Bars are designated thus — width X thickness X length center to center of holes. 
See Fig. 22. 

173. The customary' way of putting on dimension lines and figures is shown in Figs. 20, 21, and 
22. The chief pecuharity noted is that the figiires are placed on the side of the dimension line Instead of 
In a space made by bpeaking the line. This is rendered necessary by the very small space available for 
many of the dimension figures. Note way of Indicating that lengths of angles are approximate In Fig. 21. 

In a small size drawing of a part like an angle having thin legs which must be shown by two hnes 
very close together, it is not possible to use hea\^^ lines. To distinguish between the hnes of the figure 
and the extension and dimension lines really requires that the latter be made with red Ink. This is par- 
ticularly true where a blueprint is to be made. In the latter case, by using red ink the dimension and 
extension Unes appear a hght blue in the print and are easily distinguished from the white lines of the figure. 

GAGE LINES RIVET SPACING RIVET DIMENSIONS 

174. A word of explanation is necessarj^ for Table 14. The dimensions there presented are not 
to be considered as standards which have been universally adopted by construction companies, but rather 
to represent, as nearly as possible, the prevailing practice. The dimensions of rivets, for instance, wUl be 



64 

found to vary considerably, and there is no agreement among builders as to the minimum rivet spacing. 
Regarding the latter, it may be said that while the theoretical minimum space between rivets is three times 
the diameter, and the distance from the center of a hole to the edge of a plate one-half that amount, these 
rules are not rigidly adhered to in practice. As has already been stated, these distances are usually slightly 
increased. The distance from the center of a hole to the edge of a plate should be equal to two rivet 
diameters if possible. The minimum distance may be slightly decreased if the edge referred to is a rolled 
instead of a sheared one. The clearances given in the table are not so generous as those called for by some 
builders and should be considered the real irreducable minimum. The dimensions for the gage lines on 
beams, channels and angles are more nearly standard than those for the Z bars and T bars. The source 
of each of these tables is specified and the reader can use his own judgment with regard to them. 

DEFINITIONS OF STRUCTURAL TERMS 

175. Angle. — A rolled piece of steel whose cross section is L shaped. It is specified on a drawing 
as an L. 

Apex of a Truss. — This is the highest point, as Y in the Roof Truss, Fig. 21. 
Batten, Stay or Tie Plate. — A plate used at the ends of compression members to hold the two segments 

together. See Latticing, Fig. 22. 
Bevel. — The inclination of members to each other. See Roof Truss, Fig. 21. 
Bottom Chord. — The bottom member of a truss, as U-X — , Fig. 21. 

Channel. — A rolled piece of steel whose cross section is C shaped. It is specified on a drawing as a C. 
Clevis. — A forked piece with a threaded hole at one end, used for connecting a pin plate to a tie rod. 

See Fig. 22. 
Clip or Clip Angle. — A short angle used for connecting two pieces. In Chp Angles, Fig. 22, a clip is used 

at A to provide enough rivets to transmit the stress from the gusset to the angle B without unduly 

enlarging the plate. At C, a clip is used to connect the roof purlin to the top chord of the truss. 

See also. Fig. 21. 




*? 






. "H* 




t 

^ 


1 1 1 ■* ' 


-4m 


.1 


'v^ 


--.^ 


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v^-^^ 


v> 




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CVJ CVJ C\j C\4 



Fig. 22 



66 

Coping. — As applied to steel work, this is the cutting of the end of a beam or. channel to fit the contour of 
a beam or channel which it abutts at right angles. See Coped Beam, Fig. 22. 

Cotter Pin. — A pin with a head at one end and with a spring cotter at the other. It is also called a Lateral 

Pin. See Fig. 22. 
Cover Plate. — A plate riveted to the flange angles of a plate girder to increase the flange area. Also, a 

plate used to cover a part of a member which would otherwise appear unfinished. Both are used 

on the Plate Girder, Fig. 20. 
Crimped Angle. — An angle bent so as to produce a slight offset. They are used for web stiffeners and 

avoid the necessity for fillers. See Fig. 22 and note the specification regarding rivet spacing. See 

also Fig. 20. 
Eye Bar. — A rod or bar enlarged at the ends to provide for pin holes. The ordinary and the adjustable 

are shown in Fig. 22. 
Field Riveting. — This is riveting which is done outside the shop, often by hand and under conditions which 

prevent the making of tight joints. 
Filler. — Material used to fill the space between connected parts so as to preserve the right distance between 

them. It may be a washer, a ring, a piece of bar or plate or sometimes a block of wood. Note 

washers between chord angles in Fig. 21 and plate under the web stiffeners in Fig. 20. 

Flange. — The part of a beam, channel, T bar, etc., which carries the tension or compression stresses. See 
Fig. 10. 

Flats. — The common commercial designation of rectangular bar stock. 

Gage. — The distance of a row of rivet iioles from some assumed base line. See Table 14 for gages com- 
monly used for rolled sections. 

Gage Line. — The center line of a row of rivets on rolled sections. 

Gusset. — A plate to which intersecting members are attached to form a connection between them. See 

Figs. 20, 21 and 22. 
Hitch Angle. — Same as clip angle. 



67 

H Section. — A rolled piece of steel whose cross section is H -shaped. It is used for columns. 

I Beam. — A rolled piece of steel whose cross section is I shaped. 

Lacing or Latticing. — A zigzag or crisscross arrangement of bars, called Lattice Bars, which are used to 

connect the segments of compression members. Both single and double latticing is shown in 

Fig. 22. The angles specified in the figure are usually the minimum employed. 
Lug or Lug Angle. — Same as clip. 
Open Holes. — Holes left for field connections either rivets or bolts. They are always blackened in the 

drawing. See Plate Girder, Fig. 20. 
Panel. — The space between two successive chord joints. In Fig. 21, the space between U and V consti- 
tutes a panel. 
Panel Point. — The intersection of a secondary member with the chord of a truss. In Fig. 21, U, V, Y 

are panel points. 
Pin Plate. — A plate riveted to a member and provided with a pin hole which permits a pin connection 

with an eye bar or with a rod and clevis. 
Pitch. — Pitch of rivets is the distance between two consecutive rivets of a row measured in the direction of 

the row. If there are two rows staggered, the pitch is the distance between two consecutive rivets 

in alternate rows measured in the direction of the row. See Fig. 20. 
Pitch of a Roof. — The pitch or inclination of a roof is expressed by the fraction obtained by dividing the 

rise or height by the span. The pitch in the roof truss shown in Fig. 21 is /,t. The pitches most 

commonly used are I , j and i. 
Purlin. — A purlin is a cross member attached to roof trusses and to which the roof covering is attached. 

They may be beams, channels, angles or Z bars. See Fig. 21. 

Secondary or Web Members. — These are the members between the top and bottom chords of a truss or 

girder. In Fig. 21 they are V-X and X-Y. 
Separator. — This is a casting formed so as to fit the webs and flanges of two I beams which are placed side 

by side and is to preserve the spacing between them. See Fig. 22. 



68 

Sheared Plate. — This is long wide plate which has been trimmed to a rectangular form from one with 

irregular edges. 
Shop Rivets. — The name for rivets driven in the shop. 
Sole Plate. — A plate attached to the end of the bottom flange of a girder to insure the distribution of the 

pressure on the bed plate and support. See Fig. 20. 
Splice Plate. — A plate used for attaching two rolled sections or plates which are butted together endwise 

so they shall act as one piece. See web splice, Fig. 20. 
Stay Plate. — Same as batten plate. 

T Bar. — A rolled piece of steel whose cross section is T shaped. 
Tie Plate.^Same as batten plate. 
Top Chord. — The top main member of a truss. 
Truss. — A framed or jointed structure designed to act as a beam and whose members are usually subjected 

to longitudinal stress only, either tension or compression. See Fig. 21. 
Universal Plate. — Plate that is rolled in a universal mill so as to produce finished edges. Such plate is 

very long and relatively narrow. It is especially adapted for such purposes as cover plates for 

girders. 
Upset or Upset Rod. — A round rod enlarged at its ends so it can be threaded without reducing its strength. 

It is used with nuts, clevises and turnbuckles. See Clevis and Upset, Fig. 22. 
Web. — This is the part of a plate girder, I beam or channel between the flanges and is designed to carry 

the shear. Fig. 10. 

Working Lines. — These are the center lines used in laying out the parts of a framed structure. They 
usually coincide with the gage lines. In Fig. 21, the working lines are U-Y, U-X, V-X and X-Y. 
See Section 158. 

Z Bar. — A rolled piece of steel whose cross section is T. shaped. 




Fig. 23 



70 

PLAN OF BUILDING FIG. 23 

176. The plan of the Foundry Building shown in Fig. 23 illustrates the salient features of such a 
drawing. Note the following characteristics. Outside dimensions of the building are given, thickness 
of walls, center to center location of windows and doors, size of doors, location of columns, posts, parti- 
tions, and interior walls. Size of rooms is specified by measurements between the inside faces of walls 
and the center lines of partitions. The "up" and "down" of stairways is indicated relative to the floor 
shown. The permanent foundry equipment is also located. The plan presented here contains more, 
details than are usually given. 

CHAPTER VI 

GENERAL SUGGESTIONS ON TECHNICAL SKETCHING 

177. In instrumental drawing exact measurements are made, but in free-hand work measurements 
are approximated by the eye and must be largely relative. Dependence on instruments will usually ham- 
per the free-hand draftsman and a sketch that is partly free-hand and partly mechanical is unsatisfactory. 
It requires but little practice to draw free-hand lines that are fairly straight or parallel and irregular curves 
are drawn quite as easily as with instruments. A free-hand sketch, if not too complicated, can often be 
drawn in a quarter the time required for an instrumental drawing and an expert will often make a sketch 
before the other man can set his compasses. 

178. Some students draw with a pencil in one hand and an eraser in the other. It is interesting 
to watch them. They will draw half an inch of a line and immediately erase it, because of real or fancied 
error. This is entirely wrong. If the line looks wrong, leave it alone and draw another beside it, across 
it, or any way so it looks right. If this is wrong, let it stand and draw others. An ellipse thus drawn 
may look like a bird's nest, but the true line can be picked out of the collection, made heavier and the 
others erased. 

Inspection of sketches made by masters will show all this jumble of trial lines which they did not 
consider of enough importance to erase. 



71 



179. Practice at the blackboard where a free arm movement can be had is good training. In 
drawing a straight line, think of the point to which the hne is going rather than about the hand or pencil. 
Curves may be sketched in, by first spotting a few points in them. 

180. To get fan- proportions in a drawing, both the relative length and the angularity of the 
straight lines must be carefully considered. To get proper lengths, let some line of the object be taken 
as a unit and compare all other lengths with it. Then check by comparison of 

various related lines. To make these comparisons with celerity, the draftsman 
should become familiar with the appearance of different fractional divisions of a 
line. jNIeasurenient in eighths is a famihar and useful one as they are easily ob- 
tained by continued halving. See Une AB in Fig. 24. Thirds, sixths and fifths 
are also useful. To get thkds, place the pencil at 1 on CD and some other marker 
at 2; then adjust until the divisions look equal. Sixths are obtained from thirds 
by halving. For fifths use two markers as at 3 and 4 on EF and adjust until 
the distance between them is half of each end space. Sevenths are obtained on 

GH in a sunilar wa^", the markers being adjusted till 

the distance, 5-6, between them is two-thu-ds of the left end space and equal 
to the right end space. 

181. Inclination of a line is generally approximated by comparison with 
a horizontal; sometmies with a vertical if more convenient. The eye can detect 
a small error in a right angle and in parallel Unes, but for intermediate angles a 
large error will often pass unnoticed. Great care should therefore be taken with 
perpendiculars and parallels. 

^0° 182. For estimating angles uitermediate between 0° and 90°, we natu- 

rally halve the quadrant getting 45°. This is always readily tested, because it 
is a rise of one on a base of one as shown in Fig. 25. Another angle famihar to 
most draftsmen is the 30°. This can be tested by the fact that the short leg F-30 of the right triangle is 





1 

2 


h 1 

/ 
/ 

1 


^ i 1 1« 

2 

1 .n 


F, 




1 


4- 

1 , ,p 


a. r 




5 

1 


6 

1 ,;v 



Fig. 24 



/b/r Estimating 
Angles 




72 

one-half the hypothenuse B-30. By halving the 30° angle we get the 15°. Another familiar angle is the 
60°. Here, the base BD is half the hypothenuse B-60. By halving the angle between 60° and 90° we get 
the 75° angle. All these angles are in frequent use in engineering work and the student should become 
famihar with their appearance. With the quadrant divided thus into six equal parts intermediate angles 
may be approximated with considerable accuracy. 

183. If the plane of a square is parallel to the plane of projection or to the picture plane, the corner 
angles will appear as right angles and the diagonals will bisect them in the drawing just as in the original. 
If the square is placed so all its edges are oblique to the plane of projection or to the picture plane, its 
projection will be a parallelogram and its perspective a trapezium. The corner angles of these figures 
are not right angles and their diagonals do not bisect the corner angles. See Fig. 41,8, and Fig. 3. A. 

184. If the square is placed so one side is parallel to the plane of projection or to the picture plane, 
then the projection will be a rectangle and the perspective very nearly so. 

185. If an angle be placed so its bisector is parallel to one of the planes of projection, then the 
projection of the angle on that plane will be bisected by the projection of the bisector. 

186. It is therefore very important to remember, that in constructing figures whose planes are not 
parallel to the plane of projection nor to the picture plane, no use can be made of the actual angle between 
adjacent edges. 

187. A triangle should be constructed by drawing its base, its altitude, its vertex and last the 
oblique sides. To locate the altitude properly, note how it divides the base line. 

188. In the equilateral triangle. Fig. 26, the altitude bisects the base. Note that the altitude is 
approximately equal to I of the base. The vertices of the concentric triangle are on the altitude lines. 
To construct the triangle draw BC, mark its middle point D, draw AD, locate A and draw AB and AC. 
This completes ABC. To construct FGH, measure off DE as a fractional part of AD, draw FG parallel 
to BC, draw altitude CK and BL, locate F and G and draw FH and GH parallel to AB and AC. Or FH 
and GH may be located in the same way as FG, if the preceding construction gives poor results. 



73 



AD=DC= CE=EB=±AB 
FH=iABArf/iox. '^ 

r^ A<S 



7/ 


A 


A^'-^ 


f '^^-\ 


B 


D C 




Fig. 26 



Their diagonals iatersect at the 



189. In the regular hexagon. Fig. 27, the short diameter, FH. is approxi- 
mately I of the long diameter, AB. A side is equal to \ AB and the lines FH 
and GJ bisect AC and CB. The vertices of the concentric hexagon are on the 
diagonals of the outer figure. 

To draw the outer hexagon, draw AB, halve it, quarter it and draw FDH and 
GEJ. Locate F and H, di-aw FG and HJ paraUel to AB. Draw last AF. .\H, BG 
and BJ, then check by noting if opposite sides are parallel and equal to one-haK 

their parallel diagonal. The base of the nut in Fig. 45 K, 
was drawn m this way. 

190. Kectangular figiu'es are constructed without 
diflBcvdty by drawing their sides directly, 
center. 

191. After the rectangle, the circle is the commonest figure with which 
the di-aftsman has to deal. If it is remembered, that it can be iascribed in a 
square, it wiU be easier to draw, whether it is shown as a true circle or as an 
ellipse. 

In Fig. 28 a chcle is shown inscribed in a square. It touches the sides at 
the middle points. It cuts the diagonals at a distance from the center equal 
approximately to 1^ of the half diagonal. To draw the circle, mai'k its center and 
spot four points as E, F, G, and H equidistant from it. These points are needed 
not so much to produce a good curve as to insure its proper location and size. 
For the concentric circle, similar points maj^ be taken, the distance between the 
two curves being measured on a radius and as a fraction of the large radius. 
Thus in the figure this distance is ^ of the large radius. 

192. Suppose a circle is placed so its plane is obhque to the plane of 
projection, or to the picture plane. It may be proved that its projection, or its Fig. 28 



Fig. 27 




74 

perspective is an ellipse. The circle has an infinite number of diameters and one of them will be parallel 
to the plane of projection and project in its true length. This will be the longest diameter of the ellipse, 
or its major axis. In the same way, one of the diameters will project shorter than any of the others and 
this will be the shortest diameter, or minor axis of the ellipse. These two axes are perpendicular in the 
ellipse and the curve is symmetrical with respect to each. 

I .^___ ^ I 193. The projection of the concentric circle will give an ellipse similar to 

j /'"'^^^^^^^H^^''^*^^^^^ I the first. For instance if the radius of the second circle is § that of the first then 

j^ ^_ ^^_-^'I^_^?\' ^^^ radius of the inner ellipse will be f of the coincident radius of the outer 

!^"\J^'' 1^ "/ 1 ellipse. This is shown in the full fines of Fig. 29. Thus ON = | OF and OP = | OQ. 

jP-^'^^^^^--- ^ '\h ^.^ -"^ c\ 194. Returning to the circle described in Section 192, suppose a line be 

p. 29 drawn perpendicular to the plane of the circle at its center. This line will be 

perpendicular to every diameter of the circle, therefore perpendicular to that 

one which is parallel to the plane of projection and which projects as the major axis of the ellipse. By 

the principle stated in Section 184, the projection of the line perpendicular to the plane of the circle will 

be a line perpendicular to the major axis of the ellipse. 

This is one of the most important principles relating to the projections or perspectives of cylindrical 
forms and its common violation, through ignorance, results in disagreeable distortions. 

From this principle, it follows that a circle whose plane is horizontal will be represented by an 
ellipse whose major axis is horizontal. 

195. The principles explained in Sections 191, 192, and 194 apply to correct perspective drawings 
as well as to projections. In the case of concentric circles the perspective representation is slightly differ- 
ent. The inner circle is shown as an ellipse, but its center does not coincide with that of the outer ellipse. 
This is shown by the dotted lines in Fig. 29. The plane of the circle is below the eye. 

196. A square circumscribed about the circle of Sec. 192 will project as a parallelogram. The 
ellipse, the projection of the circle, will touch the middle points of the sides and have its center at the 
intersection of the diagonals. 



75 



197. The major axis should always be dra'wii or imagined '\\heu drawing an eUipse and the cm"ve 
should be made symmetrical on it. Havmg both axes given, mark the center of the elhpse and then spot 
points for the four ends of axes. Draw the curve through these four points. 

198. Referring to Fig. 46, B, let the plane of the cncle parth' shown by the arc HLK be parallel 
to the plane of projection. Let equal di\isions be marked on it as mdicated. Xow revolve the circle on 
a hne, CH, coincident with its diameter, until it projects as the ellipse of which one-half is SHJ. Any 
division point as L on the circle will, during the revolution, remain in a plane perpendicular to the axis 
and the projection of L will be foiind somewhere on a Une L^l perpendicular to CH. As the projection 
of L must also be on the ellipse, it will be found at AI. 

It is seen, that equal divisions on the cu'cle are not so on the elhpse, its projection, but that they 
shorten gradually toward the end of the major axis. This construction will give results of considerable 
accuracy, even though drawn free-hand. ^\Tien some knowledge of the rate of shortening is acquired, 
the consti-uction may be dispensed ^^-ith. The gear teeth m the drawing were spaced by the eye and not 
quite accurateh^, as the construction shows. It is true, however, that the error is scarceh^ noticeable. 

199. Having a circle and one of its diameters, if a chord be drawn parallel to the diameter and 
bisected, a diameter through the point of bisection will be perpendicular to the 

first diameter. Now place the cii-cle so its plane is obhque to the plane of pro- 
jection and the projection of the circle becomes an eUipse. The diameter and 
parallel chord project as parallels and the chord is stiU bisected. The projec- 
tion is shown in Fig. 30. 

Having an elhpse ABCD representing a circle, and a line, 1-2 represent- 
ing a diameter of that ckcle, to find the line representing a diameter perpen- 
dicular to 1-2, construct as follows. Draw a chord 3-4 of the eUipse parallel 
to 1-2, bisect it at 5 and draw the required line 6-7 through point 5 and 0, the center of the ellipse. 

200. The draftsman should acquu-e familiaritj' with the shapes of various elhpses. Several should 
be constructed accurately bj' the method sho^^^a in Fig. 30. Draw two lines AB and CD at right angles 




76 



and intersecting at 0. On the straight edge of a strip of paper or card, mark FH equal to half the desired 
major axis and GH equal to half the desired minor axis. Place the paper so that F falls on the line COD 
and so G falls on the line AOB, then move the paper about, keeping F and G always on their respective 
lines. Mark point H on the drawing at its various positions and connect them. The curve will be an ellipse. 
201. Irregular figures are best drawn by plotting as shown in the line RS Fig. 49. Select a base 
line 1-11 and divide it into equal parts. Erect a perpendicular or ordinate at each division point and 
measure off on it the required distance. 

CHAPTER VII 

SKETCHES FOR SHOP DRAWINGS AND ELECTRICAL SYMBOLS 

202. If it is desired to have a sketch accurate as to shape 
and size, it should be made on cross section paper. The kind 
ruled in J" squares is preferable, though that ruled in ^" squares is 
suitable for large drawings. 

If the piece has one or more axes of symmetry, these should be 
drawn first as center lines. If the piece has any prominent cir- 
cular parts, the view showing them as circles should be drawn 
first. Thus, in Fig. 31, the lower view of the box cap is the one 
to be started first. The dimensions being given and the scale 
of the drawing being assumed as half size, draw a horizontal and 
a vertical center line through point A. Take the radius of the 
shaft and spot points B, C, D. Draw the semicircle BCD. 
Draw in succession BE, DF, GE, HF, JG, PK, LJ and MK. 
Spot points 0, N and P, and draw arc NOP. Draw LQ and MR, 
then proceed to the top view. Draw center line Z-Z, then 1-2 and 3-4. By referring to the lower 
view, spot points 5, 6, 7 and 8 and draw in order 1-7, 8-3, 2-5 and 6-4. By referring to the lower view, 













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78 




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10 






























rr 


T 


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0/ 


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N 


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rU 


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Fig. 31 



■ 77 

spot points 9, 10, 11 and 12 and draw in order 9-10. 11-12, 9-13. 11-15, 10-14 and 12-16. Spot centers of 
bolt holes 17 and 18 and draw circles. Spot 19 and 20 and draw arcs concentric with the bolt holes. 
Draw verticals at 5, 6, 7 and 8 to meet these arcs. Draw circle for oil hole. 

Return to front view and by projecting verticaUj' from the top view, put in dotted lines for bolt 
and oU holes and the recesses cut for the nut. • 

The order of drawing Unes may be varied to some extent, but that given will enable the draftsman 
to do the work expeditiously and in ink without previous penciling. This is the kind of sketch which a 
designer most frequently uses in working out details. 

203. If the draftsman has to make a dunensioned sketch of a piece iu place on the machine, a 
different procedure is ad\'isable. The piece should be sketched, dimension hues and specifications added 
before any measurements are made. The purpose of this is to avoid soiling and obhterating the drawing 
as much as possible. There is httle advantage in making such a sketch on ruled paper, as the drawing 
is made by the eye. 

The piece to be sketched is the Rocker Arm shown in Fig. 32. It is covered with dirt and grease 
and carniot be removed from the machine. Before beginning the sketch, look the piece over carefuUy 
to determine its character. 

Draw first the ^-iew shoeing the hubs as circles. Put in center lines X-X and Y-Y the angle between 
them being estimated by the eye. Spot centers of circles and draw aU six beginning with the large hub. 
In estimating relative sizes, base the diameter of the large hub on the distance between its center and the 
left hand center. Base the diameter of the small hubs on the diameter of the large one. Base the diam- 
eter of each hole on its own hub diameter. Xext draw lines of arms basing the arm width on the small 
hub diameter. Proceed to the lower view, put in the center fine Z-Z and vertical center lines for the holes, 
^lark on vertical center lines the lengths of hubs basing the measurement on the hub diameter. Draw 
ends of hubs, determining their side limits by reference to the upper \'iew. In the same way, spot and 
draw the lines of the arms, basing their thickness on their width. Draw the vertical side lines of the holes 
and hubs. The arms being fUleted into the hubs, there wiW. be no intersection line, but the shape of the 



78 



RocHER Arm 

On£- Mal . /f!o/y-PAT. No. 394- 



COff£ HoL£S 



joint may be suggested by a line, as shown in the drawing. By showing one-half the front view in section, 
the construction is seen. at a glance, otherwise, dotted lines must be used. Draw the outline of the arm 
section. Little draft is necessary on the hubs as they are short. 

Next draw extension and dimension lines, but put 
on no figures. Make the measurements systematically, 
,y so none may be overlooked. The following order is satis- 
factory : Distance between centers of hubs ; Angle of arms ; 
Diameter and length of each hub and hole ; Width and thick- 
ness of each arm. Put on dimension figures distinctly and 
mark finished surfaces in the view where the surface projects 
as a line. Make the section lining last. Specify material, 
number required and the pattern number, if there be one. 

■z 204. If dunensions are known, and a sketch is to be 

made with some accuracy as to proportions, a scale can be 
improvised as shown in the drawing, if neither scale nor 
Fig. 32 ruled paper are available. 

205. If sketches like the preceding are made in the systematic way indicated, they may be drawn 
directly in ink. The beginner should work with ink from the start, as it trains him to look ahead and plan 
his drawing. He may spoil a few drawings at first, but a spoiled drawing is usually one of the most in- 
structive lessons a draftsman ever gets. 

CHECKING A WORKING DRAWING 

206. Even with the utmost care an error in a drawing will sometimes get by the checker and appear 
in the finished machine or structure. Such errors may often be remedied, but sometimes they prove very 
costly. All reasonable precautions to avoid them should be taken. Not all drafting offices check their 
drawings, but most of them admit the desirability of doing so. 





Fig. ji 



80 

No general brief rules can be laid down for checking a design as so many things have to be con- 
sidered. A few things that easily creep in unnoticed are as follows : Interference of parts, as might hap- 
pen with the feed handles on a lathe carriage ; Holes that cannot possibly be drilled ; Tee slots which the 
cutter cannot get into; Surfaces which a planer tool cannot reach; Castings with impossible coring. 

In checking a drawing, we shall examine to see if there are sufficient dimensions and specifications 
and if they are the right kind to secure correct construction. Important dimensions, such as center dis- 
tances, should be scanned more carefully than others. Also we must compare corresponding dimensions 
of related parts to see if they agree. Thus the bearing on a spindle must agree with the bearing in the box. 
The diameter and pitch of a screw must agree with the same dimensions on the hole into which it goes. 

The logical method is to take each piece by itself and putting yourself in the place of the workman 
go rapidly in imagination through each step in the process of making. Examine systematically the loca- 
tion, dimensions and specifications of each part of a piece. Where overall dimensions are given, see that 
they agree with the sum of the partial dimensions. Compare dimensions of fitted parts with the corre- 
sponding dimensions of the related piece. See if finish marks are complete, also if material, number required 
and any special treatment is specified. 

To illustrate, take the Spur Gear in Fig. 18. Is it cast or cut from the solid bar? Are dimensions 
for the pattern maker complete? Look for blank diameter, face width and bore. Is the finish fully speci- 
fied? Are the dimensions for the machinist complete? He will first chuck and ream a 1" hole, then he 
will put the blank on an arbor, turn it to 21" diameter, and face up the sides to |" thick. The teeth 
will next be cut. How many? for setting the index. What number, kind and pitch of teeth? for selecting 
the cutter. The arbor is now knocked out and the keyway cut on the keyseater. What is its size? Where 
is the shaft on which this gear is to be keyed? Is the bearing for the gear 1" diameter and |" long and is 
there a i"Xi" key? These questions satisfactorily disposed of, the drawing may be considered checked. 

Many variations of this method of checking will be found desirable depending on the type of work 
considered. It should be done always systematically to insure that every item is covered. If there are 
tapped holes, all might be considered at one time, examination being made for location, diameter, pitch 
and depth. 



'^>- h>^\ 




Fig. 34 



82 

EXERCISES ON SHOP SKETCHES. 

207. The following exercises have been selected to give practice in the making of rapid shop sketch- 
es. The objects should be sketched to some suitable scale, with ink, on cross section paper without pre- 
vious pencilling. Where dimensions are lacking, supply them, taking them of such size as will agree with 
the general proportions of the given figure. The exercises are arranged in groups which increase in diffi- 
culty and selections should be made from all the groups. 

1. Make a side view of each of the following objects shown in Fig. 47. Rectangular Frame 
A. — Triangular Prism B. — Regular Hexagonal Prism C. — Square Pyramid D. — Hexagonal Pyramid 

E. — B, C, D and E with part above plane x x removed. — Oblique Cone K. — Sheet metal Transition 

Connection N.^Sheet metal Boot O. — Three way Pipe P. — Hood Q. 

2. — Make a top view of — A7, Fig. 9. — AS, Fig. 9. — From Fig. 48, Angle Journal Box A. — Rod Rest 
B.— Scale Weight K.— Boiler Patch Bolt L.— Half Box M.— Stirrup V.— Bracket Y. 

3. — Make a sketch of the section cut by the plane x — x from each of the following in Fig. 47. — 
B, C, D and E. — Make a sketch of the section perpendicular to the spindle and through the oil hole in B, 
Fig. 8. 

Note. — In the following groups make working projection sketches with complete dimensions and 
specifications. 

4. — Bracket M, Fig. 34. — Jaw F, Fig. 34. — Bench Hook M, Fig. 33. — Center Rest Jaw, Fig. 44.^ 
Post, H, Fig. 52. — Flask Cope N, Fig. 33. — Blacksmith's Hardie B, Fig. 34. — Pinch Dog H, Fig. 33. — 
Gib Head Key, Tab. 6. — Block with T Slot, Tab. 10. — Several feet of an I Beam, — a Channel, — an Angle, 
— a Z Bar, — a T Bar, Tab. 14. — Lattice Bar, Fig. 22. — Conveyor Bucket D, Fig. 48. 

5. — Fillister, — Countersunk, — Button head Cap Screws, Tab. 3. — Stud, Tab. 4. — Machine Screws, 
Tab. 5. — Button, — Cone, — Countersunk head Rivets, Tab. 14. — From Fig. 33, Cope Core Print E, — 
Nowell Core Print F, — Pattern Hub Q, — Pattern with Prints K, — Chap let J. — From Fig. 34, Punch K, 
— Thumb Screw Y. — Machine Knob, Tab. 7. — Machine Handle, Tab. 9. — Cotter Pin, Fig. 22. 



Symbols for Electrical Diagrams 



Direct Curreni Dynamo , Moior or 
Qenerafor, as indicaied hy D, M, orG. 

-^THMh- Field. 







M j) Suyle Phase 



Polyphase 




'Synchronous Motor ~~ \^) 

"Aor ^enererlor, as ' ' 

\shonn by leffer. 



S 



^ 



Three Phase /nducliori Mohor 



Tkvo Phase /n</i/cf/on Mofor. 



\S.c!^ ■Synchronous Conk'erter. 



^ 



Voltmeter. 



Ammerler. 



Wattmeter. 



Watf-hoi/r-meter. 



Transformer. 



-AAAAA/- Resistance . 

--VVVVV Variable Resistance. 

-NSifiiiMAaa/- Reactance. 

-vSMfifiMfi^ Variable Reactance. 



Condenser. 
• Circuit Breaker. 

Fig. 35 



» • 



1 ^ 

! — 

-X — 




Fuse . 

S.P.S.T. Smfch-Ofoen. 

S.P.S.T. Switch-Closed. 

D.P.S.T. Sivitch . 

O.P.D.T. Smtch . 

Arc Lamp . 
Incandescent Lamp. 
Ga/ranonieter. 



l|l|l|l[— Battery. 



yVires Crossing, bu^ 
not in contact. 

IVire^s Crossing and 
making conlacl. 



84 

6.— Punched Washer, Tab. 9.— Washer N, Fig. 45.— Washer H, Fig. 48.— Plain Shaft Collar, Tab. 
19. — Conical Roll AA, Fig. 33. — Box on B, Fig. 8. — Face Plate B, Fig. 8. — Cam E, Fig. 48. — Flange Q, 
Fig. 45. 

7. — Bolt and Nut, Tab. 1 . — Square and Hexagonal head Cap Screws, Tab. 2. — Set Screw, Tab. 2. — 
Collar Screw, Tab. 4. — Eye Bar, Fig. 22. — Clevis, Fig. 22. — Reducing Bushing N, Fig. 11. — Box Cap R, 
Fig. 45. — Drill Stop, Fig. 50. — Solid Journal Box, Fig. 51. — Separator, Fig. 22. — Rod Rest, B, Fig. 48. 
— From Fig. 33, — Pocket Core A, — Plain Core Box B, — Balanced Core Box C, — Fillet D, — Metal Dowell 
L, — Cored Casting O, — Pattern and Prints P, — Core Q, — Loom Bracket Box R, — Twisted Link Y, — 
Latch Y, — Pillow Block Shoe Z, — Loom Bracket CC. — From Fig. 34, Taper Gib A, — Wrench C, — Bottom 
Swage D, — Knife Edge E, — Ratchet Pawl Q, — Stuffing Box Gland L, — Forked Link N, — Cap Ring P, — 
Tool Post Q, — Clamp Handle S, — Crank Arm Y, — Solid Journal Box W, — Clamp Jaw AA, — Wrist Block 
EE. 

8.— Flanged Tee Y, Fig. 11.— Safety Collar, Tab. 19.— Latch Handle A, Fig. 8.— From Fig. 33, 
Offset Slotted Arm S,— Tumbler T,— Bent Lever U,— Boiler Lug W,— Offset Link X,— Tumbler BB.— 
From Fig. 34, Socket Wrench H, — Angle Bracket J, — Staple O, — Jaw Clutch Coupling R, — Eye Bolt T, 
—Double Pawl X,— Wing Nut Z,— Forked Post DD.— Tailstock U, Fig. 22. 

9.— Solid Journal Box, Tab. 17.— Pulley, Tab. 20.— Spur Gear, Tab. 20.— Rigid Pillow Block, Tab. 18. 
— Angle Pillow Block, Tab. 19. — Flange Coupling, Tab. 16. — Compression Coupling, Tab. 17. — Jaw Clutch 
Coupling, Tab. 15. 

10. — Plan of a room with location of doors, windows, radiators and other prominent fittings. 

ELECTRICAL SYMBOLS FIG. 35 

208. To facilitate the rapid sketching of plans for wiring, some system of symbols for the parts 
occurring most frequently is often useful. The ones given here in Fig. 35 have been adopted by the Elec- 
trical Engineering Department of the Worcester Polytechnic Listitute. Their application is illustrated 
in Fig. 36. 



85 



VWV^-i vw\ 




y\ PttrmAsE Light AND Powcn Cwcurr 



•-»H>-^)— r 



^rw^ 




Fig. 36 

CHAPTER VIII 

QEOiMETRIC PERSPECTIVE AND ARTISTS' PERSPECTIVE 

209. The method of making a Geometric Perspective drawing has been described in Chapter I. 
It was there pointed out, that such a drawing should be \dewed from a particular point only, if it were to 
correctly represent the object. 

If one stands with his back against a wall, his arms outstretched on it and his eyes looking straight 
ahead, it is possible to detect motion of the hands. But though the angle of vision may be 180° or more, 
the angle of distinct ^■ision is certainly very small. In reading from a page held at the usual distance, 
the eye can see distinctly the word at which it is looking and indistinctly the word on either side. Beyond 
this, the ordinary ej'e does not see words distinctly enough to read them and has to be tm-ned. 

If then, we are examining a long drawing, we do not stand close to it at its middle and turn the eyes 
or head so as to get an oblique view of its ends, but we move about and stand in front of each detail to 



86 

be examined. It is for this reason, that geometric perspective drawings, so made that the eye embraces 
a large angle, are distortions offensive to the eye. Such a drawing would appear correct and without 
distortions if viewed from the right point, but it would be difficult to locate this point for an observer 
and it would be an unnatural and unsatisfactory way of looking at the drawing. 

Referring to Fig. 4, A, it is impossible for the human eye to see the front face of a cube as a perfect 
square and at the same time see the top and side faces. If the cube is placed so one face is seen as a perfect 
square, no other face is seen and if the cube be turned sufficiently to show a top and a side face also then 
the front face changes its shape, the top and bottom edges becoming inclined. 

Neither do we ever see a horizontal circle as a tilted ellipse, and the apparent shape of a sphere 
is always a circle. 

The photographic lens gives a true geometric perspective image and if on account of confined space, 
it is necessary to use what is called a "wide angle" lens, these distortions may become very great. We 
shall find in such photographs many curious representations, such as a sphere appearing as an oval solid 
similar to a hen's egg. This is due, it should be remembered, not to any defect in the lens, but to the 
geometric perspective. The eye could see a sphere the same way, if the angle of distinct vision were great 
enough. 

210. Artists' Perspective shows an object as the eye sees it. Its results are similar to what would 
be obtained, if a spherical surface were used for the picture plane in a geometric perspective, the eye being 
placed at its center. As only a very small portion of such a surface may be considered approximately 
flat, the angle of vision is of small size. A panoramic photograph is a near approach to an artists' per- 
spective, but inspection of one of these, shows new misrepresentations. The perspective is violated seri- 
ously in the matter of convergence of lines. 

It is therefore the province of the artists' perspective to harmonize all these incongruities and pro- 
duce a drawing which, though not scientifically correct, produces a pleasing and satisfactory effect on the eye. 

211. We have seen in Chapter I, that a projection drawing is simply a perspective made with the 
eye at a great distance from the object. 




SHOffTEAIING OF 



We have also noted the following facts about projection, namely. 

Lines oblique to the plane of projection do not project in their true lengths, but are foreshortened. 
The angle between two lines does not project in its true size, except tinder certain pecuhar conditions. 
The projections of parallel lines are parallel. 
<rovK H M yo Equal di\i5ions on a straight line will project as equal divisions. 

OF BviALL£Ls y^^^Y LinesparaUelto the plane of projection project in their true size and shape. 

Equal and parallel figtu-es project in equal and parallel figures, though not 
the same as the original. 

It remains, to discover how these results wiU be changed, when the eye is 
brought close to the object. 

212. The following principles are based on observation, but they may be 
^^^' '' proved by geometry*. The line of sight is the line along which the eye looks at 

the object, just as in aiming a gun. The picture plane is always perpendicular to the line of sight. 

213. In Fig. 37, is shown a ladder hing on the ground. Observ^e that lines which are parallel in 
the object, con\erge in the dra^^ Ing. Fig. 44 shows the effect of non-convei^ence 

214. Comparing the convergence of the rungs with the convergence of the sides of the ladder, 
obser\'e that the nearer lines are to being parallel with the line of sight, the greater their convergence. 

215. Parallels which are perpendicular to the line of sight show no convergence and if equal in 
length, the one furthest from the eye appears shortest. 

216. Exception. Though vertical parallels may appear to converge, they never are drawn so. 
See Section 6, and Fig. 3. 

217. In Fig. 38 is a Geometric Perspective drawing of a regular hexagon resting flat on a horizontal 
plane. Two opposite sides and their parallel diagonal constitute a series of parallel lines. There are thus 
three series, each ha\-ing its own direction. Xote that the lines of each series converge toward the same 
point. This point is called the vanishing point of the series, because if the lines were unlimited in length, 



88 



This may be seen on a long, straight stretch of rail- 



V.f;30°LEFT V.P'hS'l. 



Ere M 



V.P30niSHT 




A Regular 

OA/ A /Yofr/j:OA/rAL 
Plane, A O/AQONAL BEtnQ 
P£frP£IVOfCt/i.A^ TO THE 
P/CTC/ffE PLAf^E. 

Lll^EAR^ P£RSPECT/y£ 

^CALE "S '^CH ~ I FOOT 



EYE. (H) 



Fig. 38 



Each fAt/f or p'AfiALLEL 
SiOES CO/vlr£/r0£s TO A 
POIfvr ON THE HofffZON 

Lime. 



they would disappear at that point in the drawing, 
road track. 

218. Note in Fig. 38 that the three vanishing 
points for the sides and diagonals are on the same 
horizontal hne. 

All series of parallel lines which are parallel to 
the horizontal plane will have their vanishing points 
on the same horizontal line. This is called the Hori= 
zon Line. 

219. Notice in Fig. 37, that though the nmgs 
of the ladder are equally spaced, those furthest away 
appear closest together. 

If a straight line is divided into equal parts, those parts furthest from the eye appear shortest 
and the length gradually increases as they get nearer the eye. 

This may be seen in the spacing of ties on the railroad and on a picket fence. 

220. Fig. 39 is a drawing of three equal pulleys on a shaft. Note the difference in the shapes of 
the ellipses. 

In a series of circles, the one whose plane is parallel to the line of sight appears as a straight line, 
the one whose plane is perpendicular to the line of sight appears as a true circle, 
while circles having intermediate positions appear as ellipses with varying degrees 
of narrowness. This principle applies to other figures as well as to circles. 

It may be seen illustrated in long cylindrical forms such as boilers, tanks 
and pipes. 

221. With the exception of the variations stated in Sections 213 to 220 
or''pA%ArL''fL cpcLEs ^X/ inclusive, the principles of projection drawings apply equally well to perspective 
Fig. 39 drawings. 




89 

MODEL DRAWING 

222. A course in model drawing from the object is of value for several reasons. It gives familiarity 
with the peculiarities of artificial type forms that are found singh^ or combined in all engineering consti-uc- 
tions. It trains the faculty of exact observation. A drawing of a squash may be satisfactory, yet not 
much like the original. A drawing of a prism, a pjTamid, a cylinder, a ring, a cone must be very nearly 
correct or the error is apparent to all. Third, the outlines of such objects are not lost ui complex hght and 
shade nor in color effects. 

223. "WTien making a perspective sketch of an object, hold the drawdng board in an upright posi- 
tion so its plane is perpendicular to your sight as 3"ou look down on it. It should be held low enough, so 
you can look over its upper edge at the object and then back again at the drawing with only a slight move- 
ment of the head. 

Before beginning to draw, read again Sections 211 to 220 inclusive and the suggestions m Chapter 
VI and endeavor to apply them. Refer to them continualh" if you wish to be successful. 

Make your drawings of generous proportions. It may be easier to draw a short line than a long one, 
but it is more difficult to get proportions correct in a small drawing than in a large one. 

224. Suppose it is desired to make a sketch of the cube as sho-rni in Fig. 40. 

Sit back in your chair in an erect position with the drawing board resting in an upright slanting 
position on the knees. When looking at or testing the lines of the object, be careful to occupy always 
the same position. 

Proceed m the following order. Draw verticals of indefimte length, to represent the vertical 
edges of the right face. Estimating with the eye, decide on the relative horizontal •nadths of the vertical 
faces, then draw the left vertical of the left face. Take a point B on the middle vertical and judging the 
inclination by the eye, draw the top edge of the left face. In the same way, draw the top edge of the 
right face. The inclination of these lines may be more accuratel}^ judged, if the ej^es are closed until the 
lines are just visible. The draftsman maj' hastih' conclude that the back edges of the top face appear 
parallel to the corresponding front edges, but careful scrutiny with parth' closed ej^es will prove the 



90 



contrary to be true. Having decided on their inclination, draw them, completing the top face. Next, 
estimate the length of the middle vertical, comparing with the horizontal width of the right face. Mark 
its length and draw the bottom edges of the side faces in the same way as the top edges. 

The drawing should look pretty "scratchy" by this time if the insti'uctions in Section 178 have 
been followed. 

225. Now test the drawing by comparing lengths of lines and 
other suitable dimensions, and by measuring inclinations of lines. 

Remember that it is the apparent lengths and not the true lengths 
of lines of the object which are to be compared. 

To compare lengths of the front edges of the top face, sit in the 
same position as when drawing them. Grasp the pencil at one end by 
the fingers of the right hand, leaving the thumb free to be moved back 
and forth on the projecting part of the pencil. Without moving the 
body, stretch out the arm straight to full length, then swinging the arm 
from the shoulder, bring the pencil so it appears near the right front 
edge of the top face. Now turn the hand, or the pencil in the hand 
until the pencil is perpendicular to the line of sight. Swing the arm 
slightly and rotate the arm in the sleeve until the pencil appears to coincide with the line, the end of the 
pencil being at one end B, of the line. Move the point of the thumb along the pencil until it coincides 
with the right end of the line. The length on the pencil from its point to the thumb is the apparent 
length of the line. Without removing the thumb, swing and rotate the arm so as to bring the pencil to 
lie along the line AB with its end on A. Be sure the pencil is perpendicular to the line of sight. Note 
now, how the point B appears to divide the length from the end of the pencil to the thumb. Is it one- 
half, three-eighths or what? Having decided, compare the lengths of the same lines in the drawing. In 
making these measurements the pencil must always be held at arm's length and perpendicular to the line 
of sight, or the results of the test will be worthless. 




Fig. 40 



91 

226. To test the inclination of any line as AB. sit in the same position as when drawing the line. 
Place the board so its upper edge is horizontal and inchne it until its plane is perpendicular to the line of 
sight. Take the pencil or a straight edge and lay it flat against the face of the board allowing several 
inches to extend beyond the edge as shown in Fig. 40. Look straight at the line AB to be tested and with- 
out mo^dng the head, move the straight edge about on the siu-face of the board till it appears to coincide 
with AB. Holchng it in this position, look innnediately at the corresponding line in the di'awing and note 
if it is parallel to the straight edge. After some practice in this way, it wiU be found accurate enough and 
quicker to judge of the inclination of the line by haK closing the ej'es and comparing with a pencil held 
horizontal. Then quickly place the pencil horizontally on the drawing next the line being tested and note 
if the angle is the same. 

Test the drawing untU the correct lengths and inclinations are estabUshed, then remove superfluous 
lines. By using hght sketch lines, this task \\-ill not be an arduous one. 

227. "VMien drawing cylindrical forms, draw the ellipse first after establishing the slant of the major 
axis and the ratio of lengths of axes. Then draw the straight side lines, being careful that their direction 
is such as to make the axis of the cyhnder perpendicular to the major axis of the eUipse. 

228. The pecuharities in appearance of the conventional geometric forms are best studied in the 
regulation white models made for this purpose. A fairly large model is best for showing the outlines 
distinctly and a white surface is desirable, as the eye of the beginner is thus not confused by strong shade 
or color effects. If such models are not available, nearly all the tj^pe forms may be constructed easily 
out of cardboard. Alost of these models are duphcated in form by articles in domestic use, such as boxes, 
cartons, pans, pails, cans, funnels, curtain rings, various forms of crockery, glassware, etc. 

The convergence of parallels and shortening of equal spaces may be observed in grills, lattice work, 
fences, and rows of windows, while the appearance of parallel circles is illustrated by tanks, barrels, cement 
pipe, umbrella jars and many other forms seen every day. 



92 

EXERCISES IN MODEL DRAWING 

229. The following models taken in order will give a progressive set of exercises sufficiently com- 
prehensive. Place them on the table or floor below the eye level and draw them in various positions. 
While doing this verify and apply the principles of projection and perspective which have been previously 
stated in Sections 211 to 220 inclusive. A — Cube, B — Square Prism on end and on side, C — Square Frame 
lying flat and upright, D — Triangular Prism on end and on side, E — Triangular Frame lying flat and up- 
right, F — Hexagonal Prism on end and on side, G — Hexagonal Frame lying flat and upright, H — Square 
Pyramid on base and on side, I — Hexagonal Pyramid on base and on side, J — Cylinder on end and on side, 
K — Half Cylinder on end and on flat side, L — Flat Ring lying flat and upright, M — Cone on base and on 
side, N — Sphere, O — Hemisphere lying on flat surface and on curved surface, P — ^Torus Ring lying flat 
and upright. 

After practicing on these elementary forms, more difficult objects involving combinations of them 
may be tried. Complicated constructions should not be attempted at this stage, the endeavor being to 
fix the attention on elementary principles. Almost any simple object will be useful. Machine parts 
similar to those shown in Figs. 33, 34, 47 and 48, pipe fittings, old patterns and laboratory apparatus can 
generally be readily obtained. 

CHAPTER IX 

AXOMETRIC SKETCHING 

230. At Fig. 41, A, is shown the projection on a vertical plane of a square parallel to it. Take an 
axis line X-X in the plane of the square and through its center. If the square be revolved on this axis 
until its plane is perpendicular to the plane of projection, its projection will be a straight line as shown 
at E. 

Intermediate positions will give projections as at B, C and D. 

In the original projection at A, draw the horizontal QR, the verticals MQ and OR. 

The triangles MPQ and OPR are equal and the following proportion is true. 



93 



MQ PR 



When the square is revolved, these triangles change their form in the projection, 



OR PQ 
but it can be proved that the proportion is true for all positions between the 
extremes mentioned. 

231. This fact gives at once a quick way for drawing the projection of a 
square which is oblique to the plane of projection. Referring to Fig. 41, C, let 
it be required to constmct the projection of a square so placed that the ratio of 
horizontal distances between its three nearer corners is f. That is PR = 3PQ. 

Draw QR any desired length and take point P so PR = 3PQ. Erect verti- 
cals at Q and R. Draw jMP at any desired inchnation not greater than MP in A. 
Make OR the same fractional part of MQ that PQ is of PR, in this case j. Draw 
OP and MN parallel to it. Draw NO parallel to MP. 

232. If the true length of side of the square represented is desired, it can 
be found by noting from Fig. 41, A, that it is the hypothenuse in a right triangle 
whose legs are equal to PQ and PR. 

233. In Fig. 42, the projection CDEF of a square has been drawn by 
the method of Section 231. AC = 2BC and BD = 2AE. To complete the cube 
of which this square is the top face drop verticals at C, D and E. Draw trial 
hues for the bottom edges GH and HJ, placing them so as to make the figure 
look hke a cube. Now turn the drawing around until CDHJ becomes the top 
face and note if the drawing is stiU a good representation of the cube. It will 
probably be too taU or too short. Change the lines GH and HJ until the draw- 
ing looks like a cube in either position. 

The exact lengths of the verticals can be found by geometric construction, but the method described 
is sufficiently accurate and much quicker. 




Fig. 41 



94 



234. Find the center K, of the top face by the intersection of diagonals and draw PT through it 

perpendicular to CH. Mark the middle points of the sides of the top 
face and sketch in the ellipse which is the projection of the inscribed 
circle. Draw the ellipses for the other two faces, being careful to get the 
correct slant for the major axis. When completed, the three major axes 
should measure the same, if the work is accurate. 

Divide CE, CD, CH and PT into eight equal parts each. 




Fig. 42 



235. The three lines CE, CD and CH represent lines actually 
perpendicular and of equal length. They may be considered as axis lines 
of length, breadth and thickness. If the cube which this projection 
represents were a 1" cube, then the projection of any other rectangular 
solid could be easily drawn by imagining the object placed with its edges 
parallel to those of the cube. Direct comparison could then be made 
between the lines in the projections of the two objects. 
A circle in any face of the rectangular solid would be represented by an ellipse of the same shape 

as that in the parallel face of the cube. The size of the ellipse would be determined by a comparison of 

its major axis directly with that of the ellipse in the cube. 

236. In Fig. 43 is a sketch made in the manner just outlined. The object is the Hoist Arm Yoke 
whose dimensions are given in Fig. 9. The drawing is made of small size by assuming that the reference 
cube used, that of Fig. 42 is 4" on an edge. 

At a point draw three axis lines OX, OY and OZ parallel respectively to lines CD, CE and CH 
of the reference cube. For convenience in measurement, lay off from on OX a length equal to i of CD, 
a length equal to I of CE on OY and on OZ a length equal to i of CH. Each of these lengths represents 
an inch measured in the direction of its axis. These lengths are divided into quarters. 

Following the dimensions as given in Fig. 9, make OA 7", OB 2J" and OC 2". Draw CD parallel 
to OA, AE and CO parallel to OB, AD and BG parallel to OC. Make AE equal to OB then draw EH 



95 



Draw RS parallel 



AxoMETRic Sketch 



aiad£ Br /f£^s/ieA/ce 
ro Her CuS£. 




Hoist Arm Vokc 



and FB parallel to OA and f long. Draw HR and FS parallel to OB and 2i" long, 
to OA. Mark point J so that CJ equals 3i". :Make JK 
f", KX U", and KQ If". Draw in order QP. JL, PX, 
P^I, XL and ML, parallels to the Unes of the ear fu'st 
drawn. [Make OL' 1" and draw a parallel to OB through 
U. :\Iake CT 2\" and draw a vertical through T. The 
intersection of these two hues is the center of the f" 
tapped hole. Draw the major axis of the elUpse perpen- 
dicular to OA and base its length on the hne PT of the 
reference cube of Fig. 42. Draw the ellipse the same 
shape as that in the right face of the reference cube. 
The hole in the ear is located and the elhpse drawn in a 
similar manner. The shape of this elhpse will be like 
that in the top face of the reference cube and its major 
axis is perpendicular to OC. 

The projection of any object, however complicated, may be drawn in this way, if its dimensions are 
known. As an endless variety of reference cubes can be constructed, it is always possible to select the 
most suitable position for representing the object. 

237. A dra'R'ing made in this waj' is called an Axometric Drawing, because the directions and meas- 
urements of lines are referred to axes representing the tliree principal dimensions of an object : length, 
breadth and thickness. 

238. If Fig. 43 is held at arm's length it looks correct, but from the usual distance of about 12" 
the further edges appear longer than the near ones and the lines supposed to be parallel appear to diverge 
away from the ej^e. Correct the drawing by shortening the lines until they look right and converge the 
parallels until the}' look parallel. In other words modify the drawing, so it will not violate the princi- 
ples of perspective. In Fig. 44 is an axometric drawing of a center rest jaw. Xote that the back 



Fig. 43 



96 



AxO/if£T/ilC 




AxOM£:Tffir 
M0OIFI£D BY 
CO/i/I^S/f6£AICC 
or Py^fi^LLCLS 




corner appears tilted up and the back end appears larger than the front end. The second drawing shows 
the axometric drawing modified by introducing convergence of parallels. Although changes in the 
drawing are slight, the change in appearance is marked. 

239. In Fig. 45, are shown a number of drawings of type forms 
made in the way just described. At R, is a box cap composed of a 
semi circular shell with two ears. The complete elliptical end should 
be sketched in as indicated by the dotted lines, until the draftsman 
has become familiar with the appearance of the half cyhnder form. 

240. In the ease of truncated pyramids or cone forms, work 
with the vertex as shown in D and T. 

241. Where two irregular curves are placed symmetrically, 
F'K- '*'• draw the axis of symmetry first and plot the curves either side as in U. 

242. The nut at K was constructed by first drawing the complete base, then all the faces, last the 
ellipses and the contour at the right of them. To get the curve at the top of a face, plot its middle and 
end points. This is an Isometric drawing. 

243. At H is a drawing of the Spiral Gear Shaft of Fig. 9. Draw center line first and mark centers 
of ellipses dividing into proper lengths by the eye. Draw ellipses, observing the perspective effect of 
distance, then draw the straight sides with convergence. 

244. Threads are drawn somewhat conventionally. A series of parallel ellipses with their major 
axes not quite perpendicular to the axis of the screw will be fairly suggestive of a screw thread. The shape 
of the ellipse should be the same as the end of the cylinder on which the thread is cut. Look out for 
spaces and the shape of the curve at the side line where it forms a slight notch. Threads are shown at 
D, E, G and H. 

245. At F is a rapid sketch of a coil spring. If done accurately, the point of the loop on the right 
would be horizontally opposite the space between points on the left. 




Fig. 4S 



98 

246. At G is half of a Flange Union such as S of Fig. 1 1. Draw the central ellipse first, then the 
four small ellipses representing bosses for the bolts. The centers of the four are on lines at right angles 
in the object. Apply method of Section 199 to determine these lines. 

After completing the upper ellipses, drop verticals and draw parallels to the upper curves. This 
is an axometric drawing without perspective modification. Note how the left side appears tilted, because 
of this. All of these ellipses have horizontal major axes. 

247. In the washer at N, sketch bottom ellipse complete before drawing side curves. 

248. At E is a straight coupling like A of Fig. 1 1 . Note how the effect of a rounded edge on the 
end is produced. 

249. The character of a surface is often brought out by the curvature of lines on it. This is par- 
ticularly true of spherical surfaces. Note this in the Binder Handle at S, Fig. 45. Observe that the major 
axis of the ellipse representing the flat place on the ball is perpendicular to a radius of the sphere drawn 
from its center. 

Straight lines for the slot on B would convert the curved top into a flat one. 
At C, note that the outline of the hemisphere is made up of a semi-circle and a semi-ellipse. Also 
notice how the curved lines of the slot are determined. 

250. At Q, Fig. 45, is shown a torus ring, a form occurring in valve handles, hand wheels, pipe 
returns and bends. 

If we take equal paper circles, each with a small hole at its center, and fill a wire circular hoop with 
them, we shall have a torus ring. Each circle will adjust itself so its plane is perpendicular to the wire 
at the point where it is situated. A projection of the wire hoop would be an ellipse, as shown in the dotted 
line in Q. Each paper circle would project as an ellipse. The major axis of each ellipse would be perpen- 
dicular to the curve of the wire, i. e. to the curve of the large ellipse. Major axes of all the small ellipses 
would be equal. If all the small ellipses were drawn and a tangent contour to them made, we should get 
the outline of the ring. This outline is thus composed of curves parallel to the elliptical center line. One 



99 

extreme position will show the ring as two concentric chcles. The other extreme shows it as two semi- 
circles connected by parallel lines. 

25 1 . If it is desired to draw a return bend like J of Fig. 1 1 , draw the complete torus ring and cut 
it in halves as shown by dotted lines in Q, Fig. 45. To draw the small ellipse which represents the circular 
cut, draw the major axis perpendicular to the large ellipse curve at that point. A second diameter of the 
small ellipse, (not the minor axis) is found on the end of the oblique diameter of the large ellipse. From 
the relation of the lines the following proportion is true. 

Referring to Fig. 46, G, V-F is to V-G as D-E is to the major axis of the horizontal elUpse. 
If a quarter turn is desired, the ring may be divided into quarters in the same way and by use of the 
construction of Section 199. 

252. At L and M are shown chain and rope as they appear when hanging vertical. 

253. In sketches of sheet metal work, it is often desired to show the intersection of various surfaces. 
A pure guess will generally result in a bad representation, unless the draftsman is familiar with the different 
intersection curv^es. 

If the draftsman understands the construction of intersection curves by means of parallel cuttmg 
planes, the following method will prove useful. 

In A, Fig. 45, is given a vertical cyhnder whose axis is along 1-2. It is intersected by a cylinder 
whose axis 2-3 is perpendicular to that of the large cylinder at its middle point 2. The diameter of the 
small cylinder is one-half that of the large and its axis 2-3 is equal to the diameter of the large cylinder. 

Having drawn the projection of the large cylinder as desired, find the middle point, 2, of its axis. 
Draw the axis 2-3 of the small cylinder at any desired inclination. To find 3, draw 4-5 parallel to 2-3 and 
make 2-3 equal to 4-5. Draw the major axis of the ellipse perpendicular to 2-3 and make its length half 
that of the ellipse of the large cylinder. To find a second diameter of the ellipse (not its minor axis), draw 
8-9 a diameter perpendicular to 4-5 by the method of Section 199. Draw C-D parallel to 8-9 and of length 
equal to 8-1. , ' 



100 

In the actual object 8-9 is perpendicular to 4-5 and 1-2, therefore perpendicular to the plane 1-2-3 E 
of the axes of the cylinders. The line C-D being parallel to 8-9 is perpendicular to the same plane, there- 
fore perpendicular to the line 2-3. Line C-D must then be in the plane of the end of the small cyUnder. 

Draw the ellipse through points C, D and the extremities of the major axis, making it symmetrical 
on the latter. 

254. To find the intersection, draw first the line FEG which is the intersection of the planes of 
the ends of the cylinders. Cut both cylinders with a plane HJKL which is parallel to the plane of their 
axes. This plane will cut an element out of each cylinder, thus LH from the small and LK out of the large 
cylinder. These two lines intersect at point L which must therefore be a point common to both surfaces, 
or a point in their intersection. Other points may be found in the same way. Three or four are usually 
sufficient including those for the side lines of the small cylinder. 

255. It may be objected, that the errors in making such a construction free-hand will give worthless 
results. Experience of many years use with beginners has proved the contrary. The method with all its 
errors wiU give results far superior to those of a guess and with a trifling expenditure of time. 

256. The Axometric Drawing gives us a rapid and accurate method for making a free-hand per- 
spective drawing of an artificial object without the object or any drawing thereof, provided its construction 
and dimensions are known. 

The method briefly stated is this. First, construct a reference cube. Second, by comparison with 
it make an Axometric Drawing of the object. Third, change this Axometric Drawing into a Perspective 
Drawing by applying the common perspective principles. 

After the draftsman has followed this method for a time, he finds he can dispense with the reference 
cube and that he can introduce the perspective as he draws his lines. In other words, he has learned to 
make a perspective sketch of an object not before him and can therefore reproduce in this way what exists 
only in his mind. Such ability is of the highest value to the designer. 

257. In Fig. 46 are rapid sketches of gearing which give a test of the application of the method. 
The least possible construction was employed in each case and most of this is shown in dotted Unes. 



Sketches from Working Drawings 




Fig. 46 



102 

Auxiliary sketches indicate the way in which the drawings were built. See suggestions in Sections 198, 
199 and 251. 

EXERCISES IN AXOMETRIC SKETCHING 

258. Make Axometric sketches of the parts given in the following list, selecting one or more from 
each group. Where complete dimensions are lacking, follow the general proportions, selecting some prom- 
inent line of the figure as the unit with which all other lengths are compared. 

1. Reference Cube. — Make a reference cube with ellipses of about the same size as that of Fig. 42, 
but with a different relation between widths of the upright faces. 

2. Rectangular Prism Forms. — Square Frame A, Fig. 52 lying on its flat side and upright. — 
Rectangular Frame A, Fig. 47. — Gib head Key, Tab. 6 and Fig. 10. — Straight Flat Key, Tab. 7. — Cotter, 
Fig. 10 — Block with T Slot, Tab. 10. — From Fig. 10 and Tab. 14, a short length of an I Beam, a Channel, 
an Angle, a Z Bar, and a T Bar. — Rack, Fig. 18.— End of Plate Girder, Fig. 20. — Joints on Roof Truss, 
Fig. 21. — Column Base, Fig. 22. — From Fig. 48, Shoe J, Vise Strap O, Chuck Jaw P, Beam Stirrup V. 

3. Triangular Prism Forms. — Triangular Prism, B, Fig. 47, on side, on end and with part above 
X — X removed. — Triangular Frame, Fig. 26, lying flat and upright. — Gauge Stop, Fig. 9. — Rod Rest B, 
Fig. 48. — Conveyor Bucket D, Fig. 48. 

4. Hexagonal Prism Forms. — Hexagonal Prism C, Fig. 47, on side, on end and with part above 
X — X removed. — Hexagonal Frame, Fig. 27, lying flat and upright. — Hexagonal Nuts, Tab. 1. 

5. Pyramidal Forms. — Square Pyramid D and Hex. Pyramid E, Fig. 47, resting on base, with 
and without part above x — x removed. 

6. Cylindrical Forms. — Cylinder F, Fig. 47, lying on side and on end. — Flat and Oval Fillister 
head Cap Screws, Tab. 3. — Cyhnder Cap, Fig. 9. — Knurled head Screw, Fig. 10. — Cotter Pin, Fig. 22. — 
Stud, Tab. 4. — Core from Core Box C, Fig. 33. 

7. Hollow Cylinder and Ring Forms. — Ring D, Fig. 52, lying flat and upright. — Plain Shaft Collar, 
Tab. 18. — Punched Washer, Tab. 9. — Machine Knob, Tab. 7. — Spur Gear Blank, Fig. 18. — Worm Gear 





■ 


■ 






^ 


-5- 
A 


/' 




i 


V 








f 






Fig. 47 



104 

Blank, Fig. 18. — From Fig. 11, Straight Coupling A, Cap C, Short Nipple L, Flange Union S. — Cam E, 
Fig. 48.— Speed Cone Q, Fig. 48. 

8. Combinations of Preceding Forms. — Square and Hexagon head Cap Screws, Tab. 2. — Set 
Screw, Tab. 2. — Collar Screw, Tab. 4. — Anchor Bolts, Fig. 10. — Lag Screw, Fig. 10. — From Fig. 1 1, Plug 
D, Reducing Bushing N, Screw Union R. — I Beam and Connection M, Fig. 52. — Eye Bars, Fig. 22. — - 
Rocker Arm, Fig. 32. — From Fig. 48, Journal Lug A, Renold Chain Link C, Cast Eye R, Screw S, Wrench 
U, Clapper Box W, Open Bracket Y. — Solid Box, Fig. 51. — Pawl Friction Shoe, Fig. 9. — Wing Nut, Tab. 
7. — Flange Coupling, Tab. 16. — Solid Journal Box, Tab. 17. — Rigid Pillow Block, Tab. 18. — ^Angle Pillow 
Block, Tab. 19. 

9. Fractional Cylinder Forms. — Half Cylinder Q, Fig. 47, lying on flat side and on end. — Whitney 
Key, Tab. I . — Half Ring E, Fig. 52. — Box Cap, Fig. 3 1 . — Beam Separator, Fig. 22. — From Fig. 48, Tool 
Post Wedge Q, Half Box M. — Half Compression Coupling, Tab. 17. 

10. Intersecting Cylinder Forms. — From Fig. 1 1, Pipe Tee E, Y Branch F, Cross P, Flanged Tee 
v.— Safety Collar, Tab. 19. 

IL Divided Circle Forms. — (Section See 198.) Ratchet Wheel L, Fig. 52. — Jaw Clutch Couphng, 
Tab. 15.— Face Plate B, Fig. 8.— From Fig. 48, Face Plate F, Scale Weight K, Valve Handle T.— Spur 
Gear, Fig. 18.— Machine Hand Wheel, Tab. 8.— Pulley, Tab. 20.— Spur Gear, Tab. 20. 

12. Cone Forms, Simple and Combined with others. — From Fig. 47, Right Circular Cone H, 
resting on base and on side. Truncated Half Cone J, resting on base and showing flat side. Oblique Circular 
Cone K, resting on base. Sheet Metal Forms based on the Oblique Cone. — Transition Connection N, 
Boot O, Three way Pipe P, Hood Q, Hood R. 

Lathe Center B, Fig. 8. — Countersunk head Rivet, Fig. 10. — Countersunk head Cap Screw, Tab. 3. 
— Box B, Fig. 8. — Pan head Rivet, Fig. 10. — Blanks for Bevel Gears, Fig. 18. — Reducing Coupling B, 
Fig. 11.— Washer H, Fig. 48.— Boiler Patch Bolt L, Fig. 48.— Taper Shank, Tab. 13. 

13. Sphere Forms. — Sphere with Axis and Equator L, Fig. 47. — Ball Lever Handle, Tab. 9. — 
Button head Rivet, Fig. 10. — Button head Cap Screw, Tab. 3. — Ball Crank Handle, Tab. 9. — Cap Nut 
N, Fig. 48.— Railing Fitting, Tab. 12. 




Fig. 48 



106 

14. Torus Ring Forms. — Torus Ring M, Fig. 47, lying flat. — Valve Handle T, Fig. 48. — Machine 
Hand Wheel, Tab. 8.— Eye Bolt, Tab. 10.— From Fig. 11 (See Section 251) Return Bend J. Elbows, 
Q. T, and X. 

15. Miscellaneous Forms. — Cast Washer, Tab. 10. — Machine Handle, Tab. 9. — Latch Handle 
A, Fig. 8. 

16. Warped Surfaces. — (Represented by drawing the straight lines of the surface.) Fig. 47, 
Warped Plane S, Warped Cone T, Warped Cylinder U. 



CHAPTER X 

ISOMETRIC DRAWINGS AND CABINET PROJECTIONS 




IZ34-567a3IOII 



Method of Ofj/in'ws 

- AN iRRtttULAfi FiqUftE 
By PiOTT/AJG. 




Fig. 49 



259. In Fig. 6, C, is shown the pro- 
jection of a cube obtained by placing the 
cube so its dimensions of length, breadth 
and thickness make equal angles with the 
plane of projection. It does not other- 
wise differ from any ordinary projection. 
It is called an Isometric Projection. In 
Fig. 49 is shown such a projection of a 
If" Cube. The edges in the projection 
will be less than IJ" because of fore- 
shortening. In the same figure, is a 
drawing similar to the projection, but 
larger. In this drawing, the lines rep- 
resenting the edges of the cube are just 
\\" long. This is called an Isometric 
Drawing. It is a special form of an 



107 



Axometric Drawing, and all the principles and methods applicable to the latter apply to it. Its peculiar- 
ities are as follows. The axes of reference, BA, BG, and BC are 120° apart and a unit length on any one 
of them will measure the same as on any other. Thus the edges of the cube wiU aU be of the same length 
in such a drawing. One scale for measurement is therefore needed, instead of three as in axometric. The 
line BC is usually vertical and this makes AB and BG 30° lines. Elhpses 
for all three planes are also the same shape and similarly placed relative 
to the axis of reference. The major axis of the ellipse for each side face 
is inclined 60°. 

It is obvious that an Isometric Drawing is the simplest kind of an 
Axometric Drawing and that it is particularly adapted for instrumental 
construction. See Fig. 13, for isometric drawing of a pipe system. 

260. Referring to the Isometric Drawing of Fig. 49, two methods 
are shown for drawing the Isometric Ellipse. The one in the top face of 
the cube is an exact construction for the eight points used. These points 
are the middle points of the sides and the extremities of the major and 
minor axes. Point P is found from point L by the construction indicated. 
LO is parallel to AB. 

In the right face is showm a method employing circular arcs with 
centers at H, B, J and K. The method is approxunate onh', the error 
being indicated by the dotted arc with G as a center. 

The approximate elhpse should never be used as an intermediate 
construction for getting other figures. In the left face is shown a method 
for drawing u-regular figures of any kind by plotting. 



nut. 



261. In Fig. 45, K, is shown an isometric drawing of a hexagonal 
See also, Section 189 for its construction. 




Fig. 50 



108 



262. Isometric cross section paper is obtainable and affords a very convenient way for making 
an isometric sketch. Such an one is shown in Fig. 50 with complete dimensions. No explanation is 
necessary, beyond saying that ellipses should be drawn before the side lines of the cylinders. Such a 
drawing can be easily scaled. It is half size. 

263. Exercises. For practice work on Isometric take the same exercises that are arranged for the 
Axometric exercises, Section 258. Make an isometric drawing from Fig. 12 with different view point from 
that of Fig. 13. 

CABINET PROJECTIONS 

264. In Chapter I, it was explained that Cabinet Projection is a special kind of Oblique Projection 
obtained by placing the object and taking the projecting lines in a peculiar way. The typical form of this 
projection is shown in Fig. 4, B. 

The customary way to make the drawing is to draw one face in its true size and shape. Lines 
perpendicular to this face are drawn at 45° and one-half their true length. 

A circle in the front face is therefore drawn as a circle, but in a side face it would be drawn as an 

ellipse. The method for the ellipse in the side face is shown in 
Fig. 4, A. The curve is drawn through the middle points of the 
sides of the circumscribed square. Four other points are found 
on the diagonals from points a and b in the front face. 

265. Fig. 51 shows a Cabinet Projection with complete 
dimensions. 

266. Oblique projections, similar to cabinet projections," 
are often used in which the front face is shown in its true size and 
shape while edges perpendicular to this face are drawn at any 
convenient angle and made any convenient length not over full 
size. Fig. 7 is such a drawing. Edges perpendicular to the front 

face are 30° lines and their lengths are one-quarter size. 



P/fouecT/o/v 



7 'Scale 

HALf >5/Z£ 




109 

267. Exercises. From Fig. 47, Rectangular Frame A, Triangular Prism B, Hexagonal Prism C, 
Square Pyramid D, Hexagonal Pyramid E. — From Fig. 48, Rod Rest B, Conveyor Bucket D, Face Plate, 
F, Shoe J, Half Box M, Strap O, Wrench U, Stirrup V. 

Make a drawing similar to Fig. 7 in which the object is a straight line not parallel to any face of 
the cube and having each end in a face. 

CHAPTER XI 

COMPARISON OF METHODS OF REPRESENTATION 

268. The different methods of representation are not equally adapted to all purposes. The follow- 
ing comparison may not be agreed on by all draftsmen, but it is a fair statement. Isometric Projection 
is not considered, as it is not used. An Isometric Drawing has all its advantages without its difficulty 
of scaling. 

GEOMETRIC PERSPECTIVE 

269. Pictorially, a drawing of this kind may be very satisfactory if the visual angle is small. It 
has several unavoidable and objectionable distortions such as the tilting of the horizontal ellipse. It is 
not well adapted for rapid execution on account of necessary construction. Such a drawing should be 
made with instruments to secure a proper degree of accuracy. It is not adapted to dimensioning because 
of convergence of parallels. It cannot be used as a working drawing, because it cannot be scaled and 
because of the confusion caused by hidden lines and full lines of the object. Though its underlying prin- 
ciples are comparatively simple they are not quickly grasped. 

A drawing of this kind is especially useful for architectural drawings of buildings and manufacturing 
plants, and is sometimes the only way in which they can be represented. A photograph is a true perspec- 
tiA^e and less expensive, but in many confined situations, a photograph cannot be made. Fig. 2, A, is a 
Geometric Perspective Drawing. 



no 

ARTISTS' PERSPECTIVE BASED ON AXOMETRIC 

270. Pictorially, this is the most satisfactory of all drawings. It has no distortions and is therefore 
pleasing to the eye. It can be made free-hand with great rapidity, but not so rapidly with instruments. 
It is not adapted for dimensions, nor for working drawings, because of the convergence of parallels and 
because everything is crowded into one view. The principles on which it is based are simple and its meth- 
ods are quickly acquired. 

It is undoubtedly the best kind of a sketch for rapid and forcible free-hand illustration of the details 
of engineering construction. 

COMMON PROJECTIONS 

271. Pictorially, a drawing of this kind is apt to be deficient, because some study may be required 
in reading it. This will depend on the simplicity of the object. Hidden lines can be represented with less 
confusion than in any other kind of drawing. It has no distortions. It is adapted to rapid execution free- 
hand and yet better adapted to instrumental drawing because of its verticals, horizontals and circles which 
predominate. On account of the possible multiplication of views its carrying capacity for dimensions and 
specifications exceeds that of any other drawing. Neither can the meaning of a dimension be misunder- 
stood. Its principles are simple and quickly learned. It is above all the best drawing for mechanics and 
engineers to work by. 

ISOMETRIC DRAWINGS 

272. Pictorially, this kind of a drawing lacks the distortions of a Geometric Perspective and pos- 
sesses those due to lack of convergence. The available positions of the object are very limited. Over- 
lapping of parts and coincidence of lines often makes it difficult to read. It is adapted to rapid execution 
especially with instruments and of all the drawings showing three dimensions, it is the best adapted for 
dimensioning. It is often used as a working drawing for simple parts. It is simple in theory, usually 
easily understood and applied. A drawing of this kind is used considerably for showing interiors of build- 
ings and details of construction, as it can be quickly drawn with instruments. Fig. 6, A, is an Isometric 
thawing. It is better adapted for this illustration than a Geometric Perspective, because convergence 



Ill 

of the projection lines would gi\'e a wrong impression to a student. Isometric drawings are much used to 
record insurance sui'veys of manufacturing plants. 

OBLIQUE PROJECTIONS 

273. There is no demand for an obUque projection in which the object is placed with no face paral- 
lel to the plane of projection. Such a representation resembles a linear perspective drawing chieflj" in 
haA-ing all the distortions of the latter. It also has the distortions of Isometric and Axometric, namely, 
lack of convergence of parallels. "VMien made as explained in Section 266, and applied only to rectangular 
objects, the results are less objectionable. 

In spite of its deficiencies, it is often useful. Fig. 7 is an Oblique Projection and it is better adapted 
to the conditions than a Perspective or Axometric would have been. A Perspective would not have per- 
mitted parallel projection lines, but would have permitted bringing all faces of the cube to a position show- 
ing their true shape. An Axometric would have satisfied the first condition, but not the second. A Cabi- 
net Projection would have met both conditions satisfactorily, but would have caused bad overlapping 
of views. 

CABINET PROJECTIONS 

274. The remarks relative to distortions in oblique projections apply equally to Cabinet Projec- 
tions. An additional defect is that the object can be shown usually in only three limited positions. Its 
bad features as a working drawing are shown in Fig. 51. It should be used for rectangular forms only, as 
this avoids the worst distortions and permits rapid mechanical construction. 

CHAPTER XII 

SHADE LINES AND LINE SHADING 

275. If an object is illmninated by direct fight it tvoU cast a shadow. The outfine of this shadow 
is composed of the shadows of certain edges or lines of the object. A line which is said to cast shadow is 
one which separates a lighted surface from one that is in shade. In a projection drawing, these lines are 



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Use or Shade Lines 






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113 



nuule twice as heavy as tlie other hues and are called shade lines. The object of usiiif^- shade lines on a 
drawing is for the pictorial effect only. They impart an appearance of solidity. Shade lines are now 
seldom used on working drawings, but are often used in drawings made for purposes of illustration. 

276. Light is assumed to be coming down in parallel rays over the left shoulder of the observer as 
he stands looking at the object which is supposed to be built out solid on its projection. The slant of the 
rays is such that their projections on the planes of projection have an inclination of 45°. To select the 
lines that cast or form the shadow, the pencil may be set up as a light ray, as shown in Fig. 52, P, and 
applied to the projection. 

In the square frame Fig. 52, A, the front surface is in the light, while the surfaces at FH, GH, JK 
and JL perpendicular to the plane of the paper are in shade. 

The lines mentioned, therefore separate light from dark surfaces and will be made heavy. Note 
that the shade lines on the plan of the frame have been selected as if it were an elevation. In selecting 
shade lines, the view is always treated as if it were a front view. The various drawings in Fig. 52 fully 
illustrate present practice in use of shade lines. Shade lines for cylinders, cones and spheres are selected 
in a conventional way as indicated. Theoretically, the shading of a line should be on the outside of a 
projection, but such a rule cannot often be followed. It is more frequently put on the inside of the line 
of the projection. At K and M are drawings of connected parts which show how the shading is applied 
to avoid notching of the lines. ^^^^ ^ 

277. If it is desired to carry the pictorial effect still further, this can be done 
best by representing the light and shade effect on the surfaces. There are various 
ways of doing this, ranging from the complex productions of the artist to the con- 
ventional representations of the mechanical draftsman. The latter method only 
will be presented here, and very briefly, too, as it aims to be suggestive merely. 

The positions of object and observer and the direction of the light are assumed 
the same as for shade lines. The general appearance of surfaces having various 
positions relative to the light and to the plane of projection is fully illustrated in the 




114 

drawing of the hexagonal block shown in Fig. 53. The surface A-B is in the hght and inclined to the 
plane of projection. The part nearest the observer appears the brightest and the change in shade from 
darkest to lightest is a uniform one. 

The effect is obtained by using a line of uniform width and increasing the space uniformly from 
back to front on the surface. If this increase of space width is not uniform, the surface will appear curved. 

The surface B-C is in the light and parallel to the plane of projection. The light appears uniform 
on the surface and the effect is obtained by using a line of uniform width and a space of uniform width. 
The brightness depends on the width of line and of space, but it is better to use a fine line than a wide 
space to secure a light effect. 

The surface C-D is in the shade and inclined to the plane of projection. The part nearest the 
observer appears the darkest and the change from dark to light is uniform. The effect is obtained by 
using a heavy line of uniform width and by increasing the width of space uniformly, though slightly, be- 
tween the front and back edges. 

Some draftsmen prefer to have surface B-C the same shade as the darkest part of A-B. In this case, 
A-B should be much lighter at B. 

278. In shading the preceding fiat surfaces, a line of uniform width was used on each and the 
same method can be used in shading curved surfaces, particularly small ones. Better 
results can be obtained usually though by changing the width of both line and space. 
Consider first the convex vertical cylinder shown in Fig. 54. Referring to its 
plan showing the projections of light rays, it is seen that light striking an element R, 
22J^° to the left of the center, is reflected to the observer in a direction perpendicular 
to the plane of projection. R is therefore the brightest strip on the surface. The light 
is seen to be tangent to the surface at the element T, 45° to the right of the center. 
Element T will therefore be the darkest strip on the surface. These two lines at R 
and T divide the surface into three parts which will be considered separately. 

Pig. 54 The portion A-B as in the case of the hexagonal block, will appear darkest at 




11.5 



A, but the change from dark to hght is abi-upt near A and more gradual near B. To get the effect, start 
at A with a hue of medium width and as B is approached let the line narrow very gradually, but widen 
the space more rapidly. 

The surface from B to C corresponds approximately to the same surface on the hexagonal block 
except that there is a gradual change at B to the brightest and at C to the darkest parts of the entu-e 
surface. To get the effect, increase the width of hne and decrease the width of space verj' gradually in 
working from B to C. 

The part C-D is in the shade and inclined to the plane of projection, but also curved. It will be 
veiy slightly Ughter at D than at C. To get the effect, narrow the line, at fu-st gradually, then abruptly, 
in working from C to D and keep the space a narrow, uniform width the same as at C. 



279. 





Fig. 56 



Fig. 55 




Fig. 57 



A hollow cylinder is shown in Fig. 55 and the method of locating the dark and light lines 
get the effect, shade the portion from A to B just Uke the 
part from C to B on the convex cylinder. Shade the 
portion from B to C just like the part from B to A on the 
convex cjdinder. 

280. A shaded cone is shown in Fig. 56. The 
light effect is obtained in the same way as for the convex 
cj'hnder. As each hne must taper from base to vertex, 
use a needle to rest the straight edge against at the vertex 
and set the pen to make a fine line. Each hea\y hne is 
composed of a series of fine ones. The beginner mil get 
them too heaw unless he is careful. 

281. The torus in Fig. 57 is shaded like a convex 
cylinder, vertically and then horizontally. This gives the 
effect of double curvature. Fig. ss 



To 




1L6 

282. Ill Fig. 58 is .shown a simple method of shading a spherical surface. It does not give a correct 
effect, but the exact effect is obtained only by methods of lining which require much skill and time. 

283. A half torus or return bend is shown in Fig. 58, the effect being produced by setting the center 
of shading lines a little above the center of outlines. 

CHAPTER XIII 

FREE=HAND LETTERING 

284. Although many styles of alphabets have been devised, only a few of them are adapted to 
rapid off-hand work or otherwise suitable for drawings used in construction. The novice is often confused 
in his selection by the great wealth of available material, and it is partly for the purpose of avoiding this 
that a very limited number of styles has been presented here. If one masters thoroughly the single 
stroke Gothic, he will have little difficulty with any other style. 

Any free-hand lettering looks well, if it conforms to certain fundamental principles which insure 
uniformity in general appearance. For this reason the plainest letters, if well made, are often quite as 
effective as more ornate ones. While the general tendency is toward the use of the simpler forms, the 
decorative styles are also in frequent demand by the draftsman. These could not be satisfactorily in- 
cluded in such a brief treatment of the subject, but the treatises by Brown, Day and Strange provide all 
that could be desired along this line. A comparison of the contents of these books with the collections of 
alphabets formerly published for the use of draftsmen will afford considerable instruction in lettering as 
a fine art. To inlay the surface of a letter with mosaics and geometric designs or to drape it with biological 
rarities, does not make it beautiful. As a thing for use, its form should be recognizable, but beside this it 
may have so graceful a shape that there is pleasure in looking at it. 

Good lettering on a poor drawing will not redeem the drawing, but a good drawing may have its 
appearance ruined by poor lettering. Poor lettering affects our estimate of a draftsman's ability in about 
the same way that illegible handwriting impresses us regarding the writer. Ability to letter well depends 
on the same qualities as free-hand drawing. It is needless therefore for a student to say he cannot letter 



117 

well, that he has no talent, is no artist. For what he calls talent is merely natural ability to observe cor- 
rectly, combmed with muscular control. Inasmuch as both these faculties may be acquu-ed without 
excessive exertion, he can learn free-hand lettering by a Uttle expenditure of reason and will. 

285. Mechanical lettering differs from free-hand lettering in that the letters m their final forms 
are made with instruments although they may have been sketched first free-hand. The curved parts are 
lined first by means of the compass or curved ruler, straight parts with the tee square and triangles. A 
combination of mechanical straight parts and free=hand curved parts is usually unsatisfactory unless the 
draftsman is an expert. Care regarding tangencies of straight lines and curves is as essential as in geomet- 
ric drawing, so the process is apt to be a tedious one. This excessive amount of time devoted to a minor 
matter constitutes the chief objection to the use of mechanical lettering on commercial drawings. From 
an artistic standpoint, a mechanical letter is often objectionable on account of its extreme precision and 
exact duplication, just as a piece of machine carving is less pleasing than that done bj' hand. With free- 
hand letters, this lack of flexibility does not exist because slight variations are unavoidable and no two 
As or Bs or Cs will be exactlj' alike. 

286. \\^iile mechanical or free-hand letters may be well formed and satisfactorj^ as letters yet they 
may not harmonize with then- surroundings. Imagine the appearance of Old English type on a workmg 
drawing, or, if you will, the plain modern Gothic entwined with the traceries of a ^Moorish archwaj'. The 
primary object of words is to say something. If the statement be in the form of a notice, the simpler the 
expression and the plainer the letters the better. If, however, we have a scriptural quotation used to fill 
bare space on a church wall, then something ornamental is desirable. Thus the question of lettering quick- 
ly merges into one of decorative design and the simpler forms of letters will be found modified into unusual 
shapes more or less artistic as will be seen by reference to memorial tablets, book covers and magazine 
advertisements. 

287. Students (generally poor letterers) will often say, "Why should a draftsman learn to letter 
well; don't most drafting offices emploj' boys to do such work?" Their idea is, of course, that ia the 
development of the division of labor in the drafting office, the first man makes a sketch of the design of a 



118 

machine, a second man elaborates details in pencil, a third makes a tracing of these in ink, a fourth puts 
on dimensions and a fifth the lettering. This may be all right in theory and it is in part the practice in 
some large establishments. In the great majority of cases, however, it will be found that the draftsman 
who begins the drawing does all the work on it. The only printing he may sometimes avoid is that for 
the title. In this matter practice varies, but the end in view is to secure uniformity and to economize 
time. It is for this reason that a boy who has a natural knack at lettering is often employed at low wages 
to put in all general and sometimes the sub-titles. The general title is often printed on a press with blank 
spaces to be filled in; or. it is printed with rubber type and lined over to make the letters opaque for blue 
printing; or the title is traced from a copy placed underneath. The dimension figures and printed speci- 
fications are put on by the draftsman who knows the drawing. And these dimension figures especially 
must be so definite in form and prominent in size that they are not easily obliterated even in the blue= 
print. Too much care cannot be exercised in this particular, for a slight irregularity in the drawing may 
cost hundreds of dollars to rectify when it has been duplicated in hard metal. A beam too short or a bear- 
ing out of place is an error not easily corrected and the responsible draftsman will pass through an uncom- 
fortable season. 

FUNDAMENTAL PRINCIPLES 

288. Height and Width of Letters. The underlying characteristic of good lettering is uniformity 
in general appearance. This applies to the height and width or to the apparent area covered by the indi- 
vidual letter. Referring to Fig. 59, lines 1 and 4, we see that all the capital letters are of the same height 
and nearly all have the same width which we may style the normal width. The exceptions are the I, the 
J which is roughly |, the M which is | and the W which is | of the normal width. Figures are about 
-g of normal width. Looking at the small or lower case letters of this alphabet, we see in line 7 that 
the heights are variable. There is, first of all, a body in nearly all the letters, of a height equal to |- that 
of the capitals. Six of the letters, b d f h k 1, rise above the body to the full height of capitals, while a 
seventh, t, falls a little short of this height. Five of the letters, g j p q y, have parts extending below the 
body as far as the stems of the other letters extend above. The remaining letters aceimnorsuvwxz 



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120 

have only the body, if we except the i which has a dot. The normal width of the small letters is about 
s of that of capitals. The f i j 1 r t are narrower, while the m and w are greater than normal width. 
The ratio of normal width to height for capitals and the bodies of small letters should be about f. 

289. While the uniform heights and widths of letters as shown in the plates are satisfactory for the 
ordinary small sizes, they will often need modification in the larger ones in order to secure uniformity in 
apparent size. For instance, if the letters A B R S are all of the same width, the A will appear narrower 
than the B and the S than the R. When such is the case, the letter which seems narrow should be 
widened enough to overcome its defect. In the same way the C G and Q may appear a little too short 
especially when placed to the left of a letter like the B or E. 

290. If lower case letters are being used, the common rules relating to use of capitals should be 
followed. Words requiring Emphasis may be Capitalized, either on the Initial or THROUGHOUT. 
If capitals only are used THEY MAY BE ALL OF THE SAME HEIGHT or Initials may be Larger 
ON THE Prominent Words. A word of minor importance like the "of" Fig. 65, Title 1, line 2, would 
not have an enlarged initial unless it stood first in the line like "The" in the fourth line of the same title. 
When large and small capitals are thus used, the small ones should be about | the height of the large ones. 
As they have no parts extending below the base line, capitals permit the use of a larger letter for a given 
vertical space than is possible where lower case letters are used. This is frequently of importance when 
condensing material in a table. 

291. When letters and spaces are narrowed to less than normal width as compared with their 
height, they are said to be COMPRESSED; when they are made greater than normal width, they are said to 
be EXTENDED. Extended lettering will often look better than the normal as errors in parallelism 
are not so noticeable. The printer specifies a letter height by points. These range from 5J to 72 points 
in metal sizes and a limited range of these is shown in Fig. 64. 

292. Slant of Letters. Uniformity in the slant of letters is essential. Letters may be vertical 
as in "Worcester," may slant forward like common handwriting as in "Polytechnic" or backward as in 
"Institute." See Fig. 60. The vertical form is the most difficult as even an untrained eye notes slight 



121 



variations from the erect position. The forward slant is most used, 

especially for rapid work. The incUnation is about 22° from the vertical \/\/Q R C EI ST EI R 
or a rise of 5 on a base of 2. See Fig. 59, hne 4. A beginner will some- 
times do better with the back slant than with either of the others. It PqI Y TFOHNlC 
should always be tried, especially if the writer is left-handed. 

It is customarj' to draw the top and bottom limiting lines for let- \\s\ C/T \'T \ XT V 
tering of any kind. The slant of letters is determined by reference to these » ^ ^ vj \_ 

hnes whether they be straight or curved. For instance, the limit lines for ^'^' *" 

'■^lap of on Fig. 65, Title 2, are arcs of concentric circles. In map drawings it is often necessary to 
use irregular cur\"ed limit Unes as in "SaUsbvu-y St.," Fig. 61. Xote that the parts of the letter which he 
on the limit lines in straight lettering are found coinciding with the limit lines in curved lettering. In 
the same way the slant of any particular letter wiU be determined by the du'ection of the cm've at its 
position. Sometimes, however, in ornamental work, vertical letters are used, as in "Boynton, " 
Fig. 61. 

293. Styles of Letters. There should be uniformity in the style 
of letters employed for the same body of text and usually for the entire 
drawing. Variation in styles is permissible in titles or for pm*poses of 
classification. As to the latter, in case of maps for instance, state names 
might be in one style, cities and towns in another. The tendency, however, 
is toward uniformity even here, with variation in the size or slant only 
for different features. 

294. A common error is the mixture of capitals and small letters 
indiscriminately thus, DropForoinGS ; or the mixture of Roman and 




Fig. 61 



Gothic, thus LATHE. 

295. Spacing of Letters and Words. 

letters and the actual spaces between words. 



We must have uniformity in the apparent spaces between 
For small letters not exceeding j" high, in which the upright 



122 

part is formed with a single penstroke, the normal space width may be i or ^ of the normal letter width. 
That a definite rule generally applicable cannot be formulated is shown by the word "SMELTER," 

Fig. 62, upper line, in which the spaces between letters are all equal. On 
f-^ K J I — I —1— I — I — \ account of the large area between the L and T, the word appears to be 
J~^ \\/\ \ h li broken in two parts. If this space is reduced enough to give the appear= 

ance of uniform spacing, as in the second line, we find that the T actually 
(^ N A r" I I r~ [3 overhangs the L. The same modification of spacing will be necessary with 

O I V I L_l I L_ M the various combinations of ACFJLOPQTVWandY which, it will be 

noted, are the letters that do not fill out their parallelograms. Space let= 
'^' ters so they appear to be evenly distributed throughout the word. If we 

drop a letter out of a word thus, Labo atory, the space between the O and A is the requisite amount for 
readable spacing of words. A good phrase to remember is, "Crowd letters; spread words." It is natural 
to do the reverse. If, as sometimes happens, it is impossible to provide a proper amount of space, the 
division into words may be effected by using a large capital initial for each word. Extra space must be 
allowed for punctuation marks between letters or words. Title 3, Fig. 65, shows an exception to rules for 
spacing. 

DESCRIPTION OF ALPHABETS 

296. Two alphabet styles, the Roman, Fig. 63, lines t and 2, and the single stroke inclined Gothic, 
Fig.59, lines 1, 4 and 7, are used more than any others for drawings pertaining to engineering. The Roman 
is used especially in topographical work and the single stroke Gothic for shop drawings. This sentence 
is printed in Gothic. The word "Simple, " Fig. 63, line 11, is in Outline Gothic. In the same way we have 
Outline Roman and Inclined Roman or Italic. The alphabet given in Fig. 63, lines 3 and 4, is a modifica- 
tion of the latter suitable for single stroke work. A single stroke Gothic capital may be changed to the 
Roman by the addition of serifs, the short horizontal terminals; spurs, the short terminals projecting from 
one side of the line and by increasing the line width on certain parts thus, A to A, E to E. The Roman 
is a more elaborate letter than the Gothic, requires more time to make and is therefore less suitable for 



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Fig. 53 



124 

rapid work. The single stroke inclined Gothic being the one most easily understood and acquired is the 
style best adapted for the beginner's first attempt. It illustrates all the cardinal principles of good letter- 
ing and it is but a step from this to the Roman, thence to other more elaborate forms. See an analysis of 
it in detail under the topic, "Directions for Practice Work. " 

The letters shown in Fig. 59, lines 9 and 10, are adapted to either free-hand or mechanical construc- 
tion, but especially the latter as there are no curved parts. Lower case letters of the same style may be 
used, but they are not satisfactory from the standpoint of appearance and economy of time. Note that 
the heavy shading is on the top and bottom horizontals only. 

In lines 1 and 2, Fig. 63, we have the vertical Roman. These letters must be formed with consider- 
able care if they are to be presentable. Lack of parallelism, either in the general outlines or in the edges 
of shaded parts detracts much. The serifs, too, must curve very nicely into the parts they terminate. If 
they are tilted, the result is markedly offensive. The letters in lines 3 and 4, pig. 63, have already been 
referred to as modifications of the Roman letter suited to off-hand work. 

While most styles of letters look well in the vertical, forward or back slant position, those shown in 
lines 5 to 10, Fig. 63, are satisfactory only when vertical. They are free in style, easily made, and as such, 
well adapted to architectural drawings. Those shown in line 5 look best compressed. Of the three, 
that given in lines 7 and 8 permits most rapid work. 

In lines 11 and 12, Fig. 63, are indicated some of the possibilities in the way of adorning so plain a 
letter as the Gothic. The simpler the treatment the more pleasing the result. Many other modifications 
will suggest themselves and for those who lack originality, a look through the magazine advertisers may 
afford inspiration. 

297. Old English, Fig. 64, is used chiefly for engrossing diplomas, certificates of membership and 
similar documents. Round Writing, not given here, has been used to some extent for working drawings, 
but though it can be rapidly made, looks well and is easily learned, its lack of legibility has prevented its 
general adoption. 





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6 Point 

8 Point 
10 Point 

12 Point 



14 Point 

18 Point 

24 Point 



30 Point 

36 Point 



Fi'k. Ct4 



126 

TITLES 

298. General Character. A general title contains the principal information necessary to identify 
the drawing with the matter represented. Its location will vary according to the character of the drawing, 
being most frequentlj^ in the lower right hand corner. The size of title space depends on the size of 
sheet, those given in Fig. 65 being appropriate for sheets up to 18" x 24" in size. For a sheet 24" x 36", 
the title and letter dimensions could be increased 50% or more. The shape of title space is determined 
by the kind of drawing and the contents of the title, but it is usually rectangular with the long dimension 
horizontal. Its arrangement will be symmetrical with respect to a vertical center line. Vertical letters 
produce the best effect in a title and a mixture of vertical and inclined letters is not satisfactory. The size 
of letters and spaces between lines should be so selected that the title will appear well balanced or distri- 
buted over the space. The several parts of the title may be lettered to correspond to their importance, 
proper prominence being obtained by judicious use of different sizes and styles. See Fig. 65, titles 1 and 
2. Let the style of letters be appropriate to the character of the drawing; the fewer the styles in one title 
the better. 

299. Titles for Working Drawings. The title for a working drawing will specify the name of the 
machine or structure represented and generally the groups of parts to which the sheet is devoted. If the 
machine or structure is for some special use or location, it is often so stated. To this is added the name 
and location of the makers, the scale and date of the drawing, with the name or initials of the draftsman 
who made it. In many titles, spaces are left for the signature, by initials only, of those who trace, check 
and approve the drawing. Occasionally we find the name of the designer attached. The job or order 
number is also often placed in the title. Title 1 of Fig. 65 is a form suitable for working drawings. Titles 
for this class of drawings are almost invariably placed in the lower right hand corner close up to the border. 
They can then be referred to conveniently when filed in a drawer with many others. Every drafting office 
has its own standard title foriTi and this is of such shape and size as will meet its special needs. Though 
fanciful lettering is sometimes found on commercial drawings, the general tendency is toward extreme 



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128 

simplicity. The plain Gothic, either heavy face or single stroke, is the prevalent style employed and the 
largest letters will rarely exceed ts" in height. 

300. Map Titles. The title of a map or plan specifies the locality represented, the scale and date 
of the drawing, name of the draftsman and usually the name of the surveyor or engineer. If the drawing 
has been made for a public commission or corporation, it is customary to include the name. The location, 
size and shape of the title will be determined by the available space outside of or even on the map. A 
uniform arrangement for a series is not generally possible unless a one- or two-line title is used. Roman 
and Gothic letters, plain or simply modified, are the ones commonly used, but it is quite permissible to 
arrange them to produce an ornamental effect. Title 2, Fig. 65, will illustrate this. It also shows how 
to grade the prominence of different parts of the title. For instance, "The World" if in solid black would 
give too heavy, while if in outline only it would give too light an effect. As the most important part of 
the title it has larger letters. 

301. Architectural Titles. Titles for architectural drawings follow no rule, but are treated with 
great freedom. In the majority of cases, such a title will designate "what" and "where" regarding the 
matter represented, also the scale of the drawing. It may or may not have the date, name of the archi- 
tect, draftsman or other useful information. Its location is as variable as its contents and it is liable to 
be placed anywhere, even on the face of the drawing if such an arrangement is feasible. The size is usually 
such as to make it inconspicuous. In fact, it is often made to resemble a formal title as little as possible. 
As to shape, the rectangular is most common and the long dimension will frequently be vertical, especially 
if the style be that shown in title 3, Fig. 65. In this form the rectangle is to be filled as completely as 
possible without reference to punctuation or the division and spacing of words. Outline Roman, Old 
Roman and the styles shown in lines 5 to 8, Fig. 63, are the ones most used. 

302. Laying out Titles. To locate symmetrically a line of letters in a title gives beginners some 
trouble. If the letters are pencilled first, they can be located by trial, but this is apt to be a tedious process 
if the line be a long one or the letters other than the simplest. Consider for example in title 2, Fig. 65, 

123456789 10 11 12 13 14 15 16 17 18 10 20 2122 23 

the line, on mercator's projection. Numbering from the left and counting a space be- 



129 

twcen words as equivalent to a letter there are seen to be 23 letters and spaces. If letter widths were all 
normal, number 12. the S in ^Mercator's would be at the middle of the line. But as there is a wide letter, 
number 4, and a wide space for the apostrophe at the left of the S, w-hile at the right are two narrow letters, 
numbers 17 and 21, it is necessary to shift the center of the line a little to the left of the S. Starting then 
with the S properly placed, work both ways from the center. If appearances indicate that the end letters 
are not coming just right, a slight modification in letter and space widths will overcome the error as the 
work proceeds. It will be easier for some to first mark off in pencil the space allotted to each letter. 
On account of the difficulty of proper placing, it is ad^isable for beginners to pencil titles before mking, 
until the eye is sufficiently trained to dispense with it. 

DIRECTIONS FOR PR.ACTICE WORK 

303. Smooth, hard surface paper is the best for lettering as it helps insure a clean cut fine and 
smooth working of the pen. This is quite desirable when lettermg for reproduction. ~^Tien tracing 
cloth is used, the surface must be thoroughly rubbed with powdered chalk or pumice and all particles re- 
moved before the ink is appUed. 

304. A fine pen like a Gillott Lithographic is best for Roman letters and others having fine lines 
and shaded parts. For single stroke Gothic, a medium fine pen that has been somewhat used or a fuie 
ball point pen will work well. The prudent draftsman wiU take good care of his lettering pen, using it for 
no other purpose. It should be cleaned frequently, as ink particles collect and dry between the nibs, 
spreading them so as to render the pen useless. Water-proof black ink is most used. 

305. The upper and lower guide lines are always pencilled and to save time in practice, cross- 
section paper ruled in tenths of an inch may be used. Slant lines in pencil showing the inclination may 
be ruled in intervals all over the sheet. A rise of 5 on a base of 2 is a very good inchnation to use. Tack 
the sheet on the board in such a way that the elbow is supported when at work, otherwise the motion 
will be cramped. 



130 



/////mmm 

J^/^ I O 0/^)C~^ the mind must be concentrated on the pen point from the start to the 
fLJ^i, L, J / \.y>^ completion of a stroke. After considerable practice, it will be possible to 



306. Practice first the strokes shown in Fig. 66, taking them in 
order. They will assist in ac(iuiring the necessary swing. Blackboard 
practice on these is very beneficial. It is needless to say, that at first, 



Fig. 66 



letter automatically just as we write, but until that time it is well to 
remember that lettering is a mind as well as a hand exercise. 

307. Turning now to the alphabet of capitals in Fig. 59, lines 1 to 6, make two or three copies of 
each letter and figure. Before making a letter, note carefully in each case its general shape and propor= 
tions. The horizontal lines and enclosing parallelograms will assist in this. The parallelograms should 
always be sketched in pencil if the letter gives trouble as is generally the case with those having oblique 
parts like A, K, etc. 

308. Next study the sequence of strokes as shown in lines 2, 3, 5 and 6. Where two methods are 
given the first is desirable for rapid work, but if the beginner does not master it at once, let him try the 
second. Other ways than those given may be used if they produce good results. After going through 
the capitals in this fashion, look over the work criticallj^, mark the letters with which you have had the 
least success and devote extra practice to them. It may be said here that the enjoyable way to learn to 
letter is not to practice half a day at a time once a month, but rather to spend a quarter-hour each day. 
Practice on the letters by groups is also desirable. Thus the AKMNVWXYZ may be classed as the 
ones with predominating oblique parts, the BDEFHLPRTas the ones with horizontal parts, while 
C, G, O and Q belong to the ovals, leaving the I, J and S as miscellaneous. Attention has been directed 
to the I, J, M and W as letters of abnormal width. Other peculiarities should be noticed as follows. 
The mid-horizontal parts of the A and G and the intersection point in the Y are the same height, a little 
below the middle. The corresponding parts in the B E F H R and X are slightly above the middle while 
in the P it is at the middle. The upper lobe in the B and the S is slightly smaller than the lower one. 
Invert the letters to see it plainly. The lower oblique part of the K if extended will intersect the top end 



131 

of the upright part. The M and W must be carefully distinguished as it is a common error for a student 
to make an IVI like an inverted W, and vice versa. Among the figures, the upper part in the 3 and 8 is 
smaller than the lower. The 9 is the 6 inverted and the general outline of each coincides with that of the 
zero. 

309. Lower case letters are to be practiced in the same way as the capitals. Those of abnormal 
width, the f i j 1 m r t and w, have already been mentioned. In the abcdegopq are ovals and straight 
parts, in the f h j m and n are hooks and straight parts while the u v w x and z are like their capitals. 
Note that the cross-piece for the f and t is on a level with the tops of the short letters and that the upper 
oblique part of the k terminates at the same height. 

310. AMien an ink hue is led out of another not dry and the angle is small, a blot may form at the 
notch as is indicated in Fig. 67. Such blotting as shown in the word "pen" 
may be avoided by carrying less ink on the pen or by breaking up the stroke /O ^ ri 
as is shown in the second part of the same figure. The principle is to lead j 
into but not out of a wet line. This blotting is less liable in the Reinhardt 
letter than in the single stroke Gothic. '^' 

311. If the beginner has no immediate success with letters of normal width, let him try the ex- 
tended form, making his width equal to or greater than the height. 

312. The prominence of poor lettering may sometimes be reduced by heavy underlining. 

313. Practice lettering in pencil is not advisable when ink is at hand as it permits thoughtless 
work on account of being so easily corrected. 

314. It is useless to attempt free-hand lettering with chilled hands or immediately after severe 
muscular exertion. 

LETTERING FOR PHOTO REPRODUCTION 

315. A drawing may be reduced even to microscopic size by photography, but the chemical and 
mechanical manipulation necessary in producmg the metal plate used for printing imposes some limits. 




132 

For many drawings, it is desirable to have the final print smaller than the original because the unavoidable 
irregularities of free-hand work are thereby reduced in prominence. Some draftsmen, however, prefer 
little or no reduction because the effect of the original may be materially changed. The amount of reduc- 
tion possible is really decided by the width of the finest lines, as beyond a certain point they will become 
broken in the plate. A reduction to i or ^ the linear dimensions of the original is a good one, suitable 
for the width of medium weight pen strokes. Fig. 65 is of the same size as the original, Figs. 59 and 63 
are ^ the linear dimensions of the original while the cuts in the text of this chapter are f . a reduction to a 

size less than that of six point type used in this sentence will generally be unsatisfactory on the score of legibility r Or the Same reaSOU the Spac- 
ing for very small letters should be more open. Notches and small loops have a tendency to fill when the 

letters are small and it was to avoid this that the Reinhardt letter was 

evolved and is used on its cuts by the "Engineering News." It is only a 

slight modification of the single stroke Gothic and all the letters which differ 

^ materially are shown in Fig. 68. The principal variation is in the slant of 

AT~ ,, ^_ _, ^^ ^- the ovals which is about 45° as indicated, while in the Gothic letter the 

j^.y^ ^ ^ K Aj Cy corresponding slant would be about 60°. Compare with line 7, Fig. 59. 
I I 1 1 1 1— O' Lx w/ Another variation is in the hooks of letters such as the h, m and n where 
Fig. 68 the hook is made more pointed and leads from the straight stem at a greater 

angle. Loops are also exaggerated as in the e. The upper and lower parts 
of the 2, 3, 6 and 9 are more nearly the same size. 

3 1 6. Waterproof black ink is the best to use for reduction work as there is no danger of blurring 
it by accidental moistening. All ink lines must be jet black, never grayish. Red coloring matter is 
sometimes put in the ink to insure its photographing properly. For the same photographic reason the 
paper used should be of a bluish rather than of a yellowish tinge. 

ALTERATIONS 

317. Often a letter or part of one must be removed. The use of an ink eraser is apt to demolish 
parts of neighboring letters, but it will leave a better surface for re-inking than will a sharp knife. It is 



Ga'b dgp cj 



133 

best to pencil what is to be replaced and then use very little ink on the pen, otheiwise the lines may have 
frayed edges. If a small part is to be removed, a sharp knife will be most satisfactory. First cut lightly 
the surface of the paper at the boundary of the erasure, being careful not to cut through. Then scrape 
carefully up to the edge of this cut and you will leave a sharp clean edge on the ink line. If the surface 
is such as would be spoiled by erasure, the parts can be painted over with " Chinese white" and ink applied 
on this. 

BOOKS ON LETTERING 

318. Text Books for Students 

Lettering for Draftsmen. C. W. Reinhardt. Text 32 pages. 9 Plates. D. Van Nostrand Co. 

The Theory and Practice of Lettering. C. E. Sherman. Text 49 pages. 10 Plates. Midland Pubhsh- 

ing Co. 
Free-hand Lettering. V. T. Wilson. Text 95 pages. 23 Plates. John Wiley & Sons. 
Text-Book on Plain Lettering. H. S. Jacoby. Text 82 pages. 48 Plates. The Engineering News 

Publishing Co. 
Free-Hand Lettering. F. T. Daniels. Text 34 pages. 13 Plates. D. C. Heath & Co. 
The Essentials of Lettering. T. E. French and R. Meiklejohn. Text 94 pages. 120 illustrations. 

McGraw-Hill Book Co. 

Lettering as a Decorative Art 

Letters and Lettering. F. C. Brown. Text 214 pages. 211 illustrations. Bates & Guild Co. 
Alphabets. E. F. Strange. Text 294 pages. 197 illustrations. Geo. Bell & Sons. 

Contains also a good list of references. 
Alphabets Old and New. L. F. Day. Text 256 pages. 254 illustrations. Charles Scribner's Sons. 
Grammar of Lettering. A. W. Lyons. Text 109 pages. 93 Plates. Maclaren & Co. 



Decimal Equivalents 
of Common Fractions 



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Table No. I 



134 





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'^^ 


/;^s 


y^ 


/'^^ 


/^^ 


/^ 


2^ 


2^ 


2^ 


3^ 


HR 


^/az 


^ 


^Vaz 


'i-^ 


/^ 


l^a 


/^. 


/^ 


I'J^B 


/^ 


Z>fG 


2^ 


E 


%^ 


^4 


VSB 


Ve^ 


;^ 


;^ 


;^ 


^3 


%^ 


^^ 


'^4 


^^ 


SC 


%2 


^ 


*^ 


•%* 


■^^ 


%z 


iy,6 


/i%-4 


l'%^ 


/tt; 


l')(e 


2^ 


N 


ysz 


%* 


^^ 


% 


^6 


•^^4. 


^^4 


^/^^ 


t^ 


?^ 


/ 


/^ 


SF 


^ 


% 


>^ 


^/s 


^ 


'Xb 


^ 


?^d 


l/a 


/^ 


IH 


/>g 


Thread 


20 


/a 


/6 


14- 


/3 


/2 


II 


/o 


9 


a 


7 


7 


SR 


^/,e 


^^^ 


;^ 


^%Z 


% 


l/^z 


l/^e 


/^^ 


/;^6 


/^ 


Z^e 


2^ 


1 
UJ 

1 

1 


^ 


























Thread 


zo 


/a 


/6 


14- 


/3 


IZ 


II 


/o 


s 


8 


7 


7 


% 












1 

i 

i 

i 


^ 


























% 
















% 












v& 
















1 
















\ 


















VA 


















VA 




















1^ 




















\'/z 






















/^ 






















\% 
























2 


























2 


























zy^ 


























?X, 


























2^a 


























A 


























2^ 


























z\ 


























3 


























3 


























3ii* 






















3^ 






















iVz 






















3^a 






















5% 






















3*4 






















4 






















4 






















4^ 
















4^ 
















4^ 
















4/2 
















4^ 














4^ 














5 












^ 












13. 


5 


























Ta 


ble N 


0. i 


! 







































Fillister 


Heac 




Cap 


Screws 










Button and 


Countersunk 


Head 


1 










■^^m 

/y/////)^ 


^/////, 


. -P^^b. 


Cap Screws 




T 


i ^ 


iK^ 


Oval '^ 


\ *- 


u 


'-T 


Flat t 1 jJK-^ 


ROUN 


c^ ,1, 


T 


— > 


R-A 


Button 


H 


<5 


^ 




E V- 


Oval Cs. 


1 


s 


n^R- 


11- 


_J 


1 ■!• 




/-=o- 


k 


/^ 




FLAT C$. 




WM 




•/////y/y. 


p^^ 


1-^ 


t ^ 


'K t ) 


^U 




Wc'4 




y////)////yy^^' ^^^ 


A^ 1 


? i^ -- 


7^D If^PP 


D-D/AM. 


ya 


% 


^4. 


^6 


:^ 


?^6 


>^ 


^>B 


^ 


^ 


ya 


/ 




.h \ 


1 8 


i 


X •I § 


1 w« 




/ 


5 ^ 


\\ y 




A 


^^ 


^ 


% 


^6 


% 


^ 


;^ 


^^ 


^ 


/ 


iJ'a 


/^ 










^ T M/ 


C 


^* 


«^ 


Vaa 


'^^ 


^>^* 


^ 


^;^* 


■?^ 


■';^^ 


%a 


-^ 


Ve 


D-DlAM. 


ys 


^e 


^ 


^6 


^ 


ye 


yz 


^e 


^ 


^ 


R 


/^ 


^6 


yz 


;^ 


;^ 


^ 


/ 


/^ 


/^ 


/^ 


a 


/^ 


A 


%£- 


^G 


^6 


% 


:^ 


^4 


13/ 


i% 


/ 


IM- 


S 


.03Z 


.O't-O 


.06^ 


.07Z 


.09/ 


702 


.//4- 


.//4- 


jza 


./5J 


./5J 


./6J- 


C 


.^35- 


.OSI 


.07a 


.<79/ 


.lOZ 


.114 


.114 


.114 


./33 


./33 


T 


}4a 


'/!^ 


}^^ 


;¥* 


^a 


^^ 


;^ 


%^ 


■^^ 


^6 


ysa 


i^ 


E 


'/e 


r^a 


ye 


ysa 


'^G 


^a 


y4 


%a 


y^6 


% 


U 


%^ 


r3z 


^a 


;«^ 


fU 


%^ 


r,G 


%a 


^^* 


^^ 


^y^^ 


^ 


F 


y^ 


% 


'rsa 


ya 


%- 


'y>6 


ya 


1 


/^ 


I^S 


Thread 


4^0 


3Z 


zo 


IB 


le 


14 


13 


la 


// 


/O 


9 


8 


G 


^3a 


fu 


^z 


y^z 


'y^ 


%^ 


^^ 


^6 


5^ 


^e 


1 

1 

1 
1 

-J 


^ 


























R 


% 


^^ 


^ 


%a 


^»' 


^^^ 


^■ 


'^a 


'f^G 


/y. 


/ 


















S 


.04O 


.06'^ 


.ora 


./oa 


.'14- 


.114 


./ae 


./33 


./33 


./33 


/^ 




















T 


^* 


M^ 


ye 


^^ 


%a 


^^ 


^a 


y^ 


ya 


^a 


ll^z 






















Thread 


-#^0 


3a 


20 


la 


i& 


/-?- 


/3 


/a 


II 


lo 


!%■ 
























Z 




























^ 










-J..^ 










z'A. 


























/ 
















Z/z 


























/^ 














\ 




z%. 


























/^ 














1 ^ 




3 


























/^ 






















3'A. 


























2 






















J^ 
























J^4 






















z'A- 




















A 




















Z/a 


















4.'A 


















Z% 


1. 














^ya 
















3 


1 














^^ 




























5 


























sy^ 
















Note,— Doffed fines shon yariaHon for 0>unferju/iA ScretfS. 
Nofe-LencifhofBuffonHeadScr&Y is onc/er Heacf. 


SJ& 
















5%. 
















6 


















_ 






A 


^/7^>^ of Lou/Tfer^un/f Head '^i 


c/'(S>»' /s 0^'er /I/I. 1 



Table No. 3. 



Collar Screws 




D-DiAM. 



ya 



^6 



J^ 



%. 



'32 



'/,G 



^4 



%* 



'y&^ 



H 



%• 



'64- 



Vs^ 



y^ 



V/e 



G2 



"y64- 



% 



^e 



yz 



ya 



ys 



y3z 



% 



^ 



■^3. 



'3Z 



'ysa 



'y3a 



^6 



^e 



% 



--3; 



32 



yz 



'y,6 



^^. 



% 



% 



'^. 



yj. 



'3Z 



^y^^ 



9s 



ra 



/4 



/e^ 



yiG 



^ 



^ 



y/6 



lye 



'ye 



Studs 



Nut End 




T 

D 




D-D I AM. 



MAX. 
MIN. 



T-C.l. 



Thread 



yA. 



% 



y^e 



'^ 



20 



y,G 



y^ 



Ve 



'^^ 



IB 



y^ 



y^ 



'/6 



•% 



16 



y/6 



ya 



^ 



Va 



14- 



y^. 



y^ 



y,6 



/64 



/3 



% 



Ve 



n 



/64- 



/z 



Va 



'^y^e 



'y. 



"16 



'y3. 



'3Z 



// 



9^ 



lys 



^ 



^y^A 



10 



ye 



l^s 



ya 



^ 



lye 



/^ 



I^B 



lyfe 



lye 



ss,. 



lya 



IM- 



%* 



/3Z 



/3Z 



A.L.A.M. Stand. Bolts and Nuts 




Noi-e — Thread is U. S. Sfandarc(. 



137 



Table No. 4 



Machine ScREi^s A.SME. Stand. Mach. and Wood Screw Gage 

Qy/iL Fillister Head 

A-Diam. ^ J t L 

B=J.6^A-009 




C=0.66A-002 
D=.I73A+.0I5 

F=/J4B-f-C 

Flat Fillister Head 

B 
A = Diam. 

B=l.64A-009 
C=0.66A-OOE 
D-0.I75A+.0I5 

Flat Head 



— p 



T 



-A-^ 



1 



A=Diam. ^^f! 
D=.I73A+.0I5 



Round Head 



A = Dicfiri. 
B=l.85A-005 
C-0.7A 
D-./7JA-t.0l5 

E^ic+.oi 



-B- 



03 



c 



i_ 



-fie 










2 



8 



10 



12 



14 



16 



18 



20 



Z2 



24 



26 



28 



30 






5 



.060 



.073 



.086 



.099 



.112 



.125 



.138 



.151 



.164 



.177 



.190 



.216 



.242 



.268 



.294 



.320 



.346 



.372 



.398 



.4-24 



.450 



80 



72 



64 



56 



48 



44 



40 



36 



36 



32 



30 



28 



24 



22 



20 



20 



18 



16 



16 



14 



/4 






1^ 



.0U5 



.0595 



.0700 



.0785 



.0890 



.0995 



.1100 



.1200 



.1360 



.1405 



.1520 



.1730 



.1935 



.2130 



.2340 



.2610 



.2810 



.2968 



.3230 



.3390 



.3680 



T.A.5.M.E. V0L.Z9P39 



No. 


D/AM. 


No. 


DiAM. 


000 


.03/52 


25 


.38684 


00 


.04468 


26 


.40000 





.05784 


27 


. 4/316 


1 


.07/00 


28 


.42652 


2 


.08416 


29 


.43948 


3 
4- 


.09732 


30 


.45264 


.//048 


31 


.46580 


5 


./2364 


32 


.47896 


6 


./3680 


33 


.49212 


7 


.74996 


34 


.50528 


8 


.163/2 


35 


.51844 


9 


.77628 


36 


.53/60 


10 


.18944 


37 


.54476 


II 


.20260 


38 


.55792 


12 


.21576 


39 


.57/06 


13 


.22892 


40 


.58424 


14 


.24208 


41 


.59740 


15 


.25524 


4-2 


.6/056 


16 


.26840 


43 


.62372 


17 


.28156 


4A 


.63688 


18 


.29472 


45 


.65004 


19 


.30786 


4-6 


.66320 


20 


.32104 


47 


.67636 


21 


.35420 


4-8 


.68952 


22 


.34736 


4-9 


.70268 


25 


.36052 


50 


.7/584- 


24 


.37368 







Twist Drill and St. Wire Gage 


No. 


D/AM. 


No. 


Diam. 


No. 


Diam. 


1 


.2280 


28 


.1405 


55 


.0520 


2 


.2210 


29 


.1360 


56 


.0465 


3 


.2130 


30 


.1285 


57 


.0430 


4 


.2090 


31 


.1200 


58 


.0420 


5 


.2055 


32 


.1160 


59 


.0410 


6 


.2040 


33 


.1130 


60 


.0400 


7 


.2010 


54 


.1110 


61 


.0390 


8 


.1990 


35 


.1100 


62 


.0380 


9 


.I960 


36 


.1065 


63 


.0370 


10 


.1935 


37 


.1040 


64 


.0360 


II 


.1910 


38 


.10/5 


65 


.0350 


/2 


.1890 


39 


.0995 


66 


.0330 


13 


./850 


40 


.0980 


67 


.0320 


14 


.1820 


41 


.0960 


68 


.0310 


15 


.1800 


42 


.0935 


69 


.02925 


16 


./770 


43 


.0890 


70 


.0280 


17 


./730 


44 


.0860 


71 


.0260 


/8 


./695 


45 


.0820 


72 


.0250 


19 


.1660 


46 


.0810 


73 


.0240 


20 


.16/0 


47 


.0785 


74 


.0225 


21 


./590 


48 


.0760 


75 


.0210 


22 


./570 


49 


.0730 


76 


.0200 


23 


./540 


50 


.0700 


77 


.0160 


24 


./520 


51 


.0670 


78 


.0160 


25 


./495 


52 


.0635 


79 


.0/45 


26 


./470 


53 


.0595 


80 


.0/35 


27 


./440 


54 


.0550 







Table No. 5 



138 



1 

— 1 ' 


1*- 


Head Keys 

B=A - 


^B 


- 






h 


Lengths 

Length — 


) OF Plain 

^_L 


AND Gib 


Head Keys 

h — Length »■ 


:iN 










* 


Jl 




1 1 A 1 A 1 1 


A Taper ^'foiz" \ 


1 
Size AT A the Large 


LND OF THE Tapered Part ^ 


^+ 




A 


C 


D 


A 


C 


D 


Length 


•/e 


^. 


y^- 


^6 


% 


^6 


yz 


/,G 


% 


'/e 


%- 


'y^6 


ye 


'^e 


1 


lye 


1^ 


l^s 


/^ 


J^6 


ira 


/^e 


/ya 


M 


'Z^ 


73a 


1% 


ar^ 


1^6 


/ 














































^ 


% 


%F 


I'Jf^ 


zVfl 


/^^ 


ly^ 




















1 






M- 


'%? 


'K 


/^ 


3 


z 


z 


























1 — 




^6 


^6 


^^ 


/^ 


5/3 


2^6 


2^ 
































\ 






3 
































1 

1 














% 


^6 


'^3^ 


/^ 


3^S 


a/a 


3^ 








































1 
1 








'//6 


;^ 


'ysz 


!'/(& 


d:^s 


2-^6 


4- 
















































'/a 


Ve 


'%. 


z . 


3^ 


2/4- 


^^ 


- -1 
1 














































%; 


1 


% 


2^^ 


3^ 


Z}ff. 


.T 


1 














































% 


/^ 


^^. 


2^ 


4- 


a/r 


sy^ 


""■J 












































'Jfe 


/^^ 


^^. 


Z^B 


^ys 


z% 


e 


1 












































e/^ 


1 










































%. 


/i^ 


^ 


e!^ 


4A 


z/s 


7 


1 










































':^/6 


J:^6 


'^^ 


zyj6 


-4-^5 


Z'/e 


7yz 


1 


— 1 
1 






































'A 


/^a 


/ 


Z^s 


^^ 


Z%. 


6 




I 
1 






































%; 


m 


/^^ 


S^6 


4% 


z% 


6^2 




1 






































/ 


ly^ 


/^ 


2^ 


^^ 


?//a 


9 


1 

1 




































/^ 


/'Z 


/;r^ 


2^6 


^^ 


2^ 


S/e 








































10 




1 


































/>g 


l^a 


/^6 


2^ 


5 


J 


lO/z 




— 1 


































/A 


/■^G 


/:% 


2:;^6 


S 


^^6 


II 




— t 
1 


































IM- 


z 


J^& 


2;^ 


s/a 


A^ 


iirz 




- 1 


































l^e 


2^ 


/^ 


2^ 


S^s 


^;r^ 


/a. 


1 
































1% 


^i^ 


/^rr 


2^ 


s'^ 


,?^ 


izyz 




1 
































f^r 


p^ 


/•^ 


/''^ 


s^ 


3:^ 


/3 




1 
































ira. 


2^ 


— TTWT 


5 


s% 


3^ 


J3J^ 


&ib Head— Full line. 


1 






























i4- 


Plain — Dofted line. 


1 






























/>i6 


2;% 


/■^,e 








/4-ye 




1 

1 































139 



Table No. 6 



Square Feather Keys 



Shaft D. 



/ TO lyg 



1^6 1% 



iV/e 1% 



I '^6 iVa 



/'^e Z'/a 



Zy,€ 2% 



2^6 Z^a 



Z'Ue ZJi 



z'Pfe. sy^ 



3^G 3^6 



J-^6 5^ 



3% 3^6 



K 



fft 



1& 



^6 



'/z 



^/n 



Oe 



% 



%: 



J4 



i% 



^ 



r^e 



a-Ja]«- 



Shaft Q. 



5^ TO 4-ye 



4^6 'f-ra 



4-^/6 -^X. 



^;^ sy^ 



sWe 5M- 



5'^6 6^ 



&ff6 6%. 



eWe M- 



7^ 



^/6 



7'^6 



7M. 
~8K 



8^6 Sij 



99/6 /O^z 



IJf6 



l/a 



/4 



AT 



/^ 



/^ 



/^ 



2;^ 



2^ 



Straight Flat Keys 



L 



T 



Shaft 



/ TO /^ 



l^e Ih 



/y/6 Ife 



17/6 l/e 



i'f^6 zya 



Z^yle Z^e 



zy& Zfe 



Z'^G z'/a 



z% sye 



3^6 3% 



3^6 3^3 



3'J^6 3ye 



W 



^ 



;^6 



Ve 



y,6 



'/z 



ya 



//6 



^ 



ye 



^6 



??6 



rsi 



^ 



/^ 



^2 



';^. 



'%, 



'3Z 



'/^ 



"■sz 



/3g. 



ya 



Shaft 



3^T0^^ 



-^J^ 4-f& 



'^^G 4-% 



4-'ye sy. 



sye £% 



S'^e 6^ 



ef/e g^ 



6^6 /4 



7^6 /^ 






BWToJi 



W 



iy,G 



lya 



ly^. 



I^s 



lys 



Ife 



1% 



rye 



Z 



zyz 



y/€ 



% 



% 



^ 



l^e 



/^s 



ly^- 



1% 



/^ 



Machine Knobs 




5^ 



-^ 



^6 



■76 



% 



'A 



'I& 



^ 



% 



'16 



% 



llj 



% 



%. 



B 



y,6 



% 



'16 



% 



/7^ 



^<S 



"/ 
/I6 



Z7/ 



5^. 



'32. 



%. 



IS/ 



% 



'^/e 



l^s 



l^s 



1^6 



/^ 



/^ 



/^ 



/^^ 



/^ 



/^ 



/^ 



/^ 



/;^ 



z;^ 



^^ 



^^ 



a^ 



^e 



% 



y,€ 



V^e 



'/6 



'y^. 



'/z 



y/6 



'/6 



^y,6 



^/,. 



'/6 



/3k 



'3Z 



^3^ 



'3Z 



•y 

/3i 



'32 



'ya 



ys 



■y 



'32 



^, 



'3Z 



f^. 



'/6 



yu 



'/6 



^A 



'/6 



^6 



f,6 



^A 



'16 



'/6 



V,6 



% 



'/6 



% 



'16 



% 



'/6 



% 



06 



% 



'/6 



H 



K 



1^. 



'/6 






'3Z 



'/6 



y^ 



^ 



'3Z 



3/ 
//e 



'/6 



/ye, 



'/6 



/e 



% 



}f6 



y/6 



^6 



Va 



% 



'/6 



y,i 



'/6 



//6 



/^Z 



^6 



'/a 



3/ 
/31 



'3Z 



'^6 



'A 



'32 



9^6 



'/a 



%. 



'32 



IT/ 
//6 



'/6 



y4. 



yj. 



'JZ 



l^e 



'/6 



ye 



'^6 



yt. 



ys. 



'3Z 



1^6 



ya 



lys 



^. 



'32 



K 



1/4. 



ya 



/ya 



^. 



'32 



^ 



/4 



/ya 



%. 



'32 



y^- 



~m 



ys 



ya 



WiNG Nuts 




ys 



^6 



y^ 



yf6 



'/6 



% 



'A 



'/6 



^ 



^/ 



'/6 



% 



^40 



^Z4 



13/ 
/6< 



'6* 



y4. 



/^ 



'^ 



2y 

/64^ 



'y3. 



'32 



'y 

/3i. 



'32 



33/ 



'64- 



^Z 



y^ 



"/ 

/3i. 



<3Z 



y^e 



'/6 



yz 



% 



'/6 



% 



y,6 



^ 



8 



^. 



'3Z 



^. 



ye 



/3/ 
/3Z 



yz 



y/& 



zy 

/3Z 



;^ 



27/ 

ysi 



'32 



//6 



y3. 



'32 



yy^ 



'/6 



'y 



'32 



yz 



'y 
y3z 



^. 



'/6 



% 



"/ 

y/6 



'/e 



;¥ 



y32 



yf6 



/3/ 

y3z 



yz 



s/ 

y/e 



21/ 

y3z 



^ 



2y 
/32 



'yy6 



'/6 



W 



Tho, 



y. 



'/6 



^ 



y 

/3i 



'32 



Zl/ 
/3. 



'3Z 



40 



y6 



732 



^. 



'32 



'y 



'/6 



3Z 



y 



'3Z 



^ 



'/6 



ya 



/<r. 



zo 



^2 



^ 



ya 



//z 



18 



ysz 



'46 



ya 



w 



/'^6 



16 



ya 



y. 



'/6 



^k 



'32 



/% 



'32 



14- 



ya 



y/i 



'/6 



^. 



'J2 



Z^ 



/3 



;§-. 



'32 



yz 



^6 



2% 



'3Z 



/Z 



^62 



yz 



^ 



z% 



'/6 



// 



Table No. 7 



140 

















1 

-w— 

R 












Machine Hand Wheels 








} 


/ 

/ 

Pratt «<Whitn 




1 


• 




^- 


-H 


ok- 








EY Co. 


- J- 


/m!f^ 




, . 




12 


— 


^ 


V- 


-^ 


vm 




/^ 


^ t 




S. 


V 






\ 


^ 


Sect 




Y 


^ 


L 


r * ///^ 




Ari. 




•m& 


w. 





■11 < 


^^.^ 


hr 








+ 




\ \ \ 


N. ^ 


^ 




m 


m 


r^ii) 


v^ 




>/ 


ION 


*G 




7\ 






V^ 


■^ Wl-A 


B-> 


H 


'— 


A 


B 


C 


D 


E 


F 


G 


H 


K 


L 


M 





Arms 


Spline: 




Hand. 


P 


Q 


R 


s 


Tap 


U 


V 


w 


Y 


3 


f 


n. 

16 


s 

8 


f 


^ 


5- 
/6 


1 

4- 


15 
3Z 


13 
3Z 


I 

4- 


3 
/6 


5 


Tl 3B. 




00 


/6 


1 
4- 


If6 


s 


tI-^* 


3 
S 


1 
-*- 


il 


lit 


4 


II 

16 


13 


i 


i 


6 


IS- 
33 


JJ- 

3Z 


S 
8 


1 

Z 


32. 


7 
32 


' 


' x-L 
76 ^3a 







1 
4- 


3 

a 


If6 


f 


(f ff 


32. 


/I 

32 


# 


^ik 


^i 


7 

8 


li 


1 


7 
/6 


3. 
4- 


1 

2 


1 


3 
4 


1 

z 


JJ_ 
3Z 


1 
4- 


' 


32-^64- 




/ 


1 


9 
16 


2 


i 


f-^4 


IS. 
32. 


/3 
32 


^ 


2 — 


J 


T 

8 


Ik 


Its 


2. 
16 


7 
8 


J2 


/s 

3Z 


7 
8 


a 


3 

a 


4- 


tt 


3 X ^ 




/ 


JL 
4- 


3 
/6 


2 


f 


'1 H 


/3- 
■32. 


/3 
3S. 


IS 
/6 


2f 


6 




1^ 


l-k 


;i 




a 


S 

a 


16 


ik 


1 
z 


y-z 


" 


' X -L 

a^^ 16 




2 


16 


9 
/6 


-el- 


1 


*' rf 


/ 


7 
16 


1 


3i 


7 




l-k 


If 


^ 




J3_ 

/e> 


13 
/6 


IS 
/6 


8 


1 


f 


'/ 


JL X J- 

S /6 




3 


5. 
/6 


s. 

8 


2f 




•t It 


/9 
3S 


32 


l-k 


^^ 


8 


. I 


/^ 


If 


/ 




7 

8 


4- 


1 


Si 
8 


9 
/6 


f 


* 


-LX-i- 




4^ 


3. 
3 


i 


H 


1 


tt K 


/9 
3Z 


/ 
2 


/i 


^i 


9 


la 


li 


/^ 


/ 




1 


7 
8 


l-k 


* 


9. 
IS 


T 


It 


• X J- 




4- 


3 

a 


5- 

a 


H 


s. 


ir tt 


13 
3Z 


X 
2 


li 


-^i 


10 


, 1 

14- 


1/6 


/^ 


7 




li 


1 


Ik 


i 


8 


^ 


/» 


/6 ^ 3Z 




5 


7 
/6 


73 
16 


^/i 


1 


^-^0 


Zl 
3Z 


^ 


l£ 


H 


II 


1 1 
14- 


1/6 


/^ 


7 
8 




1^ 


I^S 


If 


1 


f 


7, 
/& 


*■ 


3 X J- 




S 


7 

/a 


1^ 
/6 


^^ 


1 


II tl 


3S. 


9 
/6 


/.f 


^i 


IZ 


1 7 

1/6 


2 


/# 


7 

-a 


, 1 
'4- 


A-f 


1 


//i 


l-k 


^ 


h 


It 


/6^ 3Z 




6 


7 
/& 


8 


^f 


/^ 


X_/6 


i 




//i 


^/i 



141 



Table No. S 



Ball Crank Handles 



Machine Handles 



Standard Washers 


















A/ /j M 


1. ofMach.Nand/&. 


No. 


A 


B 


c 


D 


^ 


r 


G 


H 


d 


K 


L 


M 


1 


Z'/s 


/4 


IM. 


% 


/32 


^ 


'A 


'/z 


^^ 


'A 


^. 


1 


Z 


J^ 


/'4^ 


Ih 


/^e 


2a- 

x3i 


%- 


%z 


% 


"/ 


% 


% 


/ 


J 


4- 


/^ 


/J 


ly^ 


/^^ 


% 


%z 


% 


%z 


%. 


'A 


2 


4- 


4i 


/#. 


iZ 


/#. 


/^ 


'/s 


/9/ 


%. 


'/e 


% 


'/z 


2 


5 


5 


'^ 


^4 


/^ 


/^ 


4e 


% 


% 


'/z 


'/s 


'/z 


3 


6 


5^z 


2 


£4 


/^ 


If. 


1 


%- 


% 


'A 


% 


yz 


J 


7 


6 


2^e 


Z>z 


1^8 


1^8 


1 


%- 


% 


y^ 


Viz 


^ 


J 


8 


SJk 


Z'^6 


2^^ 


/^8 


/^ 


/ 


%- 


% 


yz 


/^e 


% 


4 


9 


7 


2^8 


3 


/^ 


/I 


/ 


'4. 


% 


% 


/4 


% 


^ 


10 


7i 


2^8 


j4 


/^ 


/J 


1 


;^ 


'^s 


9/ 


/^ 


% 


5 


II 


8 


J^ 


3'1 


/# 


/^ 


/4 


% 


% 


% 


/^ 


^8 


5 


12 


8'/a 


Jl 


3Z 


/4 


/#. 


/^ 


h 


/ 


% 


/^ 


% 


6 


/J 


9 


J^ 


5% 


/^ 


/-I 


/^ 


;^ 


/^. 


^6 


/^e 


% 


6 




No. 


A 


B 


C 


D 


£ 


r 


G 


H 


J 


R 




1 


zl 


/z 


ysz 


'Me 


%z 


yz 


^e 


yz 


^ 


M- 




Z 


2h 


% 


ye 


'^e 


%z 


ya 


ye 


y,e 


^6 


^6 




3 


dye 


^ 


ys 


1 


yz 


% 


^ 


ya 


ye 


ya 




4 


3yz 


^ 


ysz 


1^6 


%z 


r^ 


'/6 


% 


V/a 


'Vsz 




J 


4- 


Va 


'/e 


lye 


^/e 


'J'sz 


V/& 


^ 


yz 


ye 




6 


4% 


Ve 


y,z 


1^4. 


Tsa 




%z 


'^6 


y,6 


y,6 





Ball Lever Handles 
-A 




rai 6-/5-30 

|<— /3 ->|/4 doei noi 
af^ly to this. 



No. 


A 


B 


c 


D 


E 


F 


G 


H 


N 





p 


1 


4'i. 


Sfs 


/ye 


Ve 


ye 


ye 


y4- 


^ 


ye 


yz 


/ 


Z 


Sk 


4^6 


/yz 


/ 


'ye 


yz 


'y/6 


ye 


ya 


yz 


//. 


3 


eyz 


5 


/h 


/ 


y^ 


^ye 


/ 


ye 


ye 


yz 


/4 


4- 


jyz 


6 


/^ 


/ 


^ 


% 


/ 


% 


ye 


ya 


m 


5 


sya 


eye 


jh 


/ye 


^4- 


ye 


/^. 


'ye 


ye 


ye 


/ye 


6 


9 


Zf. 


/^ 


/^6 


% 


fe 


/ja 


% 


ye 


^ 


/h 



% 

\ 

1 


~5 

1 


1 

1 




is 

11 

1-^ 


Me 


>4 


^6 


/* yfAiioo 


yA- 


ye 


^ 


16 y^ 


I5SQ 


ye 


ya 


ya 


16 ye 


IIZO 


ya 


ye 


1 


14^ 


680 


ye 


yz 


lA 


/4 4; 


430 


yz. 


% 


/ye 


/2l. 


Z70 


% 


ya 


lyz 


12 ^ 


Z30 


% 


% 


/y4 


10 M, 


/30 


y4. 


% 


z 


/oM-^ 


/OO 


ya 


'yfe 


2A 


d yjz 


75 


/ 


lye 


zyz 


9 A 


62 


/ya 


IM 


Z'4 


9 ^a 


5Z 


ly^ 


lya 


3 9 ^^ 


40 


/ya 


lyz 


J^ 


8 Z 


3Z 


iy2 


ih 


J^ 


8 1. 


28 


lya 


1^5^ 


6 1* 


Z4 


iy4iya 


4 


8 Z 


ZZ 


yye 


z 


4y4 


8 ^ 


19 


z 


zye 


4y 


8 ^ 


/7 


Z^f- 


zys 


4% 


6 Ji. 


/3 


zyz 


zye 


5 


5 ^l 


// 



Table No. 9 



142 



Cast Washers 




s 
a 



3_ 

8 



'i 



li 



1^ 
IK 



li 



1^ 
14- 






2^ 
C4. 



^i 



3- 



^4- 



^4 



S^ 
•^4- 



ei 



7i 



^i 



B 






I R 



li 



^i 



'=8 



2-^ 



3i 



4^ 



/i 



/i 



/I 



/I 



li 



3Z 



\k 



ih 



If. 



I- 

'32 



1^ 
I 8 



li 



2^ 



31 
3Z 



'3Z 



lie 



li 



li 



1^ 

'8 



/i 






3Z 



3Z 



J. 

3Z 



3Z 



11 
3Z 



3Z 



9, 



li 



li 



1^ 

18 



li 



I4. 



Spring Cotters 




BWG D Length -L 



i3 



IZ 



II 



10 



8 



9. 

64 



IL 
64- 



II 
64- 



4 TO 2' BY 4tH5 



iToei 



i' TO 3 



I TO 3 



I TO 4 



li T0 4 



,|.~T0 4-' •• 

"^ ALSO 5' 



2' TO 4" BY 4tH5 
ALSO 5"- 6' 



TO 4" BY 4-^5 
ALSO 5'- 6" 



T- Slots 




4 

/6 

.g 

/6 



J. 

/6 



/i 






B 



3Z 



2. 
32 



7_ 
3Z 



3, 
32 



3Z 



3Z 






/3 
16 



16 



J£ 
16 



1^ 



1^ 

1/6 



I- 



Ji 



/6 



X 
/6 



3_ 

16 



3. 

/6 



3_ 

4- 



ii 



li 



1^ 

1/6 



1/6 



Eye Bolts 




D 



li 



li 



li 



1^ 

'8 



li 



li 



'/6 






^k 



^h 






^/6 



2^ 



3^ 



'/6 



3i 



^i 



H 



B 



'^8 



S| 



^5 



3^ 



^1 



4i 



4i 



H 



^i 



5^ 
^6 



6^ 



6^. 



16 



Ih 



li 



/i 



'/& 



1^ 
I e 









2^ 
'^8 



H 



si 



H 



3- 

•^■4- 



H 



3^ 



3^ 



li 



//i 



''6 



18 



2i 



2| 






2^ 

^4- 



^4 



3i 



3^ 
^4- 



H 



/6 



J_ 
4- 



/i 



/6 



li 



5_ 
16 



1^ 
'8 



3_ 
8 



li 



X 
16 



1^ 

'a 



i 



li 



li 



a 



^i 



j± 

16 






3_ 
4- 



2^ 



/6 



H 



R 



5. 

/6 



X 

/6 






5. 
s 



16 



3. 
4- 



X 
6 



9. 
le 



Ik 



li 



li 



If. 



If6 



1^ 
1/6 



143 



Table jmo 10 





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■-li-i(NCOCO-*lOCD00^INTt(cOa> 

1— 1 1— 1 r-H f— 1 .— 1 


t-^cOt^aiiOCDCO'^(M002i— <t^iOTt< 
OlM00rt<O00t>-(N(^00i0^Ot0O 
iOt^O'O05C0O'0t~i-ic0C000i0C0 




^rt(N(NCOC<0-*>OCOOOO^OO'* 

r-H 1— 1 r-< I— 1 


i-li-l.-l(N'^lOcO00O5i-iiO00'-i 

^ 1-1 1-1 (N 


ca 

c 

CO 


■B3JV 


c 

& 

I 


OOi-l0502C0051>00<OOI> 

CO^OirOCOOiO'0>00(NOOOiO«OCOf-i(N(MT(< 
>000500000CC>OOOOOOOCOC£10000^0J(M C^TOOS 

O'-i'-HMiooo-^occt^cooot-CiOsoor-ot^oooo 


CC0005^0 0-HCO"-OOM33CD05t^COcO(M-*CDlM 

COCOCOCO<N'-<I^iCCOOcOiO'^OOaiI>t^cOClcDCO 

00'-i<N-5»(t^!Nt^02(M"JOOO'*CO.-<<32^CD'*CO-* 


l>Oi-ii00^05r~M<-*CD>OiC05IM 

"^"^t>-^HC0Tj<^H0i05(Nr^cDC0O<N 
Oi-l<NC0050'!fOI>l>CT!05CDi-it-l 

i-IN-^iOl^OlC^OOt^t- 

1-1 1-1 (N CO 


.-l<MC0-*l>05(MiO0S0000O<M00>CC<:) 

l-H 


rt-MiMTjicDOO'-iTfOOinTfiOOO^OO 
^^>-i<NCO-*iOI>0 

1-H 


o 


aDBjjng 

JO ■%i bg 
J3d qjSnaq 


1 


^OcC»OcD03C0O®C0O0500t^cDiOiO"*iC0C0C0(M 


-*it^cOiO-*00'-i'-<C003iO'*COOOt^O-*0!'005 
Tt'OcD'OCDaiCOOCDCOOroOOt^cD'O'OTlfCOCOIN 


li5 05 '♦^ t^ t^ 1— 1 CO 
U5-^OOi— ii-<C005iOi^cD00t*O"<S' 
lOCOOSCOOCOCOOOJOOt^CDlOlO-^ 


CO 

u 

u 

a 
o 


Oit^iO-^MCMC^M-H,-!,-! 


05(^^0■*CO(N(N(^^.-^rtrt 


^CO(N(NIN^rt-H 


ssanjiaiqx 


d 


00 00 -^ 02 00 Tf lO -* ■* t^ ':0 I> «0 05 .-H O) tH {£> lO lO 
CD00a5O'-'C0^^i0Oi-i(NMTt<iC00O(N"*ic0t^t^ 
OOOi-i.-i,-i,-i,-It-ic^)(N(M(MO)(M<NCOCOCOCOCCCO 


CO t^ OJ I-- (N 'S* CO .-1 Tji ,-1 ,-1 o lO t^ 
O(N(Nrt<i0000lO<M00O(N^CDt^C0OOOOO 

^i-irH.-ii-irtrt(M<NC^COC0C0C0C0-*iOiOiOiOiO 


OOTt<T}<oOCO(M OOlNtNOOOiOiOio 

c3>i-icoooo'a<coO"a(ooi-iu5or^i> 
(Ncococo^i^iocococDr-t-oooooo 


jajacDBiQ 
[Bujajiij 


CO 

1 

-T3 


TP CO rj Tt< t^ o t^ i^ ■n 00 CO 00 lo 1(5 CO .-< t^ 00 

t^OO>(N(N-*OO^OCOCO'*lMO'^ONOOCOrtOO 
C^COTfOOOOCOCOO-^OiOOiOOOOOiOiOOO 

■-l.-li-i(N(NCOCOTf<Tt<iOCDt>r^OOO"(M 

.— I I— ( rH 


lO^--iC^ICD^(N^COiO<N0000 CO^ioioiO 

Oa5iN^COiCt^05CO^CTnO.-<00'-iiO(N(MlMiOiC 

(NiMTt<iOr-O5C^Tt<O5CO00CO00lN00l>COCOCOt^t^ 

•-^.-^.-||^^C^COC0^TflOcDI>00O5'-l 

I— 1 


TriNI>iOOO-HiOTt<cOCO-*COOiOU3 
Tf(NOOOOOOCTi>OOOi-<COCDCDl>-t^O 
lM-*iOOOO'*t^(Nl^i-i'00000000 


CU 


i-l-Hi-llNNCOCOiJi-^iCCO 




IBaja^xg 




lO »0 lO lO lO CO "5 i(5 lO lO 

O ^ t^ Tfi ic i-H U2 l^t^ CD (M 04 ca IM »0 ic lO 

Tt'iOcDOOOCOCDOlCOOOiOO'OOiOCDCOCOcOt^lX^ 

■^rH,-irHcil>ic0li-^lC"5CDI>0603O'-lC^ 

T— 1 ?— 1 1— 1 


lO lO lO lO iO CO lO IC »0 lO 

O 'J' t^ •* >0 1-1 CD t^ t^ CD (N <N iM iM lO lO 

TJiir5CD00OC0CO050000>OO»OO»OCOCDC0C0t^r~ 

rt-H«^IM(NC0T}<Tliloir5CDr-00»O(N 

»— 1 I— 1 


lO mo CO U5 lo lo 

Tl< lO 1-1 CO O I^ t^ O CO !N IN IM 

00OC0cDasC000l0Ol«O"5CDCDC0 

i-li-i--Hr-l(NNCO-*-*lolOCOt»00 




azig 
[Buirao^ 


12; 


f^»r-H'«*»HNp:Hi— I H^HnC^ '^CC HNTji HNLO CD t* 00 05 O '— t (M 

i-H^HlMCO*^ 1— 11— It-) 


1-1 .-1 IM CO ^ T-i ^ 


HNwhfi-H MHiT*ac^l H«CO t-4M-<ti T*<lo CD t^ X 

1-H rt (N CO -* 



Table No. 11 



144 



OiOSS 



Ofoss-SlO£ Outlet 



DH 



B 



C 

T 





■*-yi^f<-o- 


i \ 


t 


J^ 


hBH< 


;k-c 


D 


{(C^ 


< I 


D 


\^ 


h^ 


B 


\ 


1 





C 



Fittings for Pipe Railings 

Te£-5/de Outlet 





«-/» ^ 


*-£»- 


i ^ 


t 


h- 


iS^C 


rh^c 


D 


^/T 


-^ 




|v^^ 


- 1 



Tee 

-A -*{<-/?- 



Elbow 



ELBonSiDE OunaT 



W\ 



D 



J. 



T 






-D- 



A 



K-c 




'^J" ELBOtv-SiDE Outlet ■4S TeeS/oe Outlet 



45° Tec 




ACOFJN 



Floor Flange 



J 

I 



\, y E ^ U-N-SIOE OFSfl.-A 




■45° Floor Fu^ge 



Note — Dimensions are a/sproximafe. 



I «^/\ X 


1 


y 


t l^>- 


^<— 



P//^ 



z? 



A- 



L 



M 



N 



O 



n Wboo 
^ Saten 



J_ 
S. 



3 



31 
32 



'8 



a 






'3S 



1^ 



/-k 



1^ 



I _ 
8 



3 



l-k 



/6 



1_ 
2 









No. 9 



' 3Z 



' 8 



5_ 

a 



/tI 






' /6 



1/6 



/i 



a 



AS 
/6 



1^ 
1/6 



J_ 
S, 



3_ 

a 






1^ 



//3 
'3Z 



/6 



/ /6 



^^32 



/ ft 



li 



I /G 



3_ 

/& 



//k 



I Ed 



Z. 



3^_ 



3_ 

a 






/4- 



4-^ 



J_ 
2 



2- 



1^. 



'32 






3_ 
4- 



/# 



:,Z3 
'32 



'a 



^/6 



' /6 



J_ 



' /& 



129 
'32 



3 



3_ 
8 



H 



/^ 

'e^- 



'^ -4- 



/3 

/e 



z^ 
^/& 



3^ 



z-J- 



"^ 8 



^4- 



/& 



/-k 



2-1- 
8 



/6 



& 



19 



145 



Table No. 12 



Diam. Ploq Small £ne/ 
J ^~ ^^'^^ oF Tontrue 



No. 



—H-Depfh ofHo/e — 
-B'Lennfh of Shan A - 



STANDARD TAPERS 



S- Ocfit/i of Shank 




M- Taper per foot 
d- Diam. of Tongue 
N~ Taper par Inch 



mm'/. 



-K- 



D 



B 



H 



K 



W 



R 




P 
t 

CO 
CO 

O 

n 



1 

2 

3 

4 

5 

6 

7 

8 

9 

9 

10 

10 

11 

12 

13 

14 

15 

16 



.20 


.2390 


li? 


H 


ItV 


1^ 


f 


.25 


.2994 


lr\ 


lA 


1t\ 


Ui 


i 


.312 


.3953 


2 


'AV 


2* 


IH 


# 


.35 


.4020 


H 


If 


If 


n^ 


u- 


.45 


.5229 


If 


2A 


u 


iH 


i 


.50 


.5989 


2f 


2|^ 


2i 


2U 


i 


.60 


.7250 


3 


3f 


3* 


2|f 


if 


.75 


.8984 


'^h 


4i 


Bf* 


BH 


1 


.90 


1.0667 


4 


4f 


4* 


3^ 


1* 


.90 


1.0770 


4i 


5 


4f 


4i^ 


H 


1 . 0446 


1 . 2596 


5 


6tV 


5A 


4|i 


h'^ 


1 . 0446 


1.2888 


5U 


6| 


5}t 


5H 


lA 


1.25 


1.5812 


61 


7U 


«J 


«H 


lr\ 


1.50 


1.7968 


H 


8^ 


7i 


6H- 


u 


1.75 


2.0729 


71 


m 


7i 


TA 


li 


2. 


2.3438 


8i 


9* 


8f 


^-h. 


i-U 


2.25 


2.6146 


8| 


10 


8^ 


m 


IH 


2.50 


2.8854 


9i 


10^ 


9| 


9 


n 



.135 
.166 
.197 
.228 
.260 
.291 
.322 
.353 
.385 
.385 
.447 
.447 
.447 
.510 
.510 
.572 
.572 
.635 



s 

IB" 
4 



TB" 

H 
i 

9 
TIT 

9 
T^ 
ZX 
"3 2 

f 

* 

37 



4-S 
TF 



.170 


i 


A 


.030 


lA 


.500 


.220 


A 


A 


.030 


H 


.500 


.282 


A 


A 


.040 


2f 


.500 


.320 


¥'2 


A 


.050 


m 


.500 


.420 


i 


A 


.060 


2A 


.500 


.460 


=^V 


A 


.060 


2| 


.500 


.560 


A 


t 


.070 


m 


.500 


.710 


H 


f 


.080 


H 


.500 


.860 


f 


tV 


.100 


4f 


.500 


.860 




A 


.100 


4f 


.500 


1.010 


A 


A 


.110 


m 


.5161 


1.010 


7 


A 


.110 


m 


.5161 


1.210 


A 


i 


.130 


7H 


500 


1.460 


i 


* 


.150 


Hl 


.500 


1.710 


i 


^ 


.170 


8A 


.500 


1.960 


A 


f 


.190 


9A 


.500 


2.210 


A 


* 


.210 


9H 


.500 


2.450 


f 


1 


.230 


m 


.500 



.0416 

.0416 

.0416 

.0416 

.0416 

.0416 

.0416 

.0416 

.0416 

.0416 

.043 

.043 

.0416 

.0416 

.0416 

.0416 

.0416 

.0416 



H 
CO 

W 

CO 

f< 

O 





1 

2 
8 
4 
5 
6 
7 



.252 


.356 


2 


m 


2A 


Iff 


A 


.160 


J. 
4 


.24 


1^ 


T^ 


.369 


.475 


2* 


2A 


2A 


2A 


f 


.213 


A 


.35 


n 


A 


.572 


.7 


2A 


BA 


2* 


2^ 


i 


.26 


s 


H 


i 


i 


.778 


.938 


3,\ 


B| 


H 


•^A 


lA 


.322 


fir 


f 


A 


T.''^ 


1.02 


1.231 


4A 


4i 


H 


H 


li 


.478 


i 


U 


ki 


A 


1.475 


1.748 


5A 


6 


H 


4ff 


H 


.635 


f 


IM 


i 


f 


2.116 


2.494 


H 


8 A 


n 


7 


If 


.76 


* 


2 


* 


* 


2.75 


3.27 


10 


n& 


m 


9^ 


2f 


1.135 


If 


211 


1* 


f 



.04 
.05 

.06 
.08 
.10 
.12 
.15 
.18 



2^ 
2f 

n 

3A 

4^ 
5f 
8 



.625 
.600 
.602 
.602 
.623 
.630 
.626 
. 625 



.05208 

.05 

.05016 

.05016 

.05191 

.0525 

.05216 

.05208 



Table No. 13 



146 




Gag£ Lines — Rii^et Spacing — Rii^et Dimensions 

t-A- 



I Beams Carnegie 


Oepfh 


Weight 


A 


Max. 
Riifef 


2A- 


SO -100 


4- 


V8 


20 


80-100 


4- 


1% 


20 


65-75 


zyz. 


II 


18 


55-70 


J^ 


II 


15 


80-100 


5k. 


n 


15 


60-75 


3^ 


6/4. 


15 


42-55 


3 


II 


/Z 


40-55 


3 


U 


IZ 


M-^5 


zh 


II 


10 


25-40 


2h 


u 


9 


ZI-35^ 


Zkz 


II 


8 


I8-Z5!i 


zy^ 


u 


7 


15-ZO 


zy^- 


Ve 


6 


IZk-l7Ji 


z 


II 


J 


dkrl4i 


ih 


Vz 


4- 


7J^-I0i 


lyz 


n 


3 


5k-7h 


/^^ 


V8 




K^^ 



Channels Carneai^ 


Depth 


tVeight 


A 


Max. 
RWet 


15 


45-55 


ly^ 


^ 


J5 


33-40 


I'A 


// 


12 


30-40 


2 


II 


12 


ZOJk-25 


I'A- 


II 


10 


25-35 


2 


ft 


10 


15-20 


lyz 


" 


9 


20-25 


m- 


U 


d 


I3yrl5 


/% 


If 


8 


l6-kr2/A 


/>£ 


It 


8 


II^-I3M 


/^ 


" 


7 


ll^-ldi 


/^ 


ys 


7 


3h-l4A 


/A 


II 


6 


/3-/5Ji 


/% 


1 


6 


8-m 


1/8 


n 


5 


d-l/^a 


/A 


/z 


5 


eyz 


/ 


H 


4 


5y4r7A 


/ 


// 


3 


4-6 


% 


ys 




Z 2 Zt 



fAfmiiV/^ 



For 8 only 



>\ 



ANQLES AmcK Br. Co. 


Leg 


A 


B 


c 


Max. 
f^i^et 


6 


4^ 


5 


3 


V8 


7 


4 


2^ 


J 


II 


6 


3yz 


Z^4 


2>2 


II 


*e 


3>i 


ZVz 


2^ 


a 


5 


3 


2 


/^ 


u 


4 


2^ 






II 


iVz 


2 






II 


3 


/^ 






II 


2^ 


1% 






3/^ 


ZYz 


iVa 






% 


2^ 


ly^ 






II 


2 


lye 






'/Z 


\% 


1 






II 


l/z 


Vs 






Va 


ly^ 


^ 






II 


1 


9fe 






'A 




* For thick, o^'er ^ 




Z -BAf^S Amer Br. Co. 


Norn. 
Well 


Thick. 


A B 


Max. Riv. 
A B 


6 


%-ya 


2^ 3 


V8 


Vs 


5 


%-;^ 


zys 


Z'^ 


n 


II 


5 


'A-ys 


2 


Z'/z 


" 


" 


4 


^/a-% 


2 


z 


y4- 


II 


4 


%-^/6 


l/a 


2 


II 


" 


4 


y^-ys 


1% 


2 


II 


" 


3 


V/^-yz 


1% 


lyz 


H 


54 


3 


y^-ye 


lyz 


lyz 


II 


II 



Minimum Clearances 



( 



H 



H=K 



< 



\\\^h\^ 



± 






Al/N. Rivet Spacing 





<^> 


,L. 


M 






( ),., 










T T T 


■ 



& 



^ 



/f/ir/ET Dimensions 



Diam. 



Va 



'/ZL 



Va 



'V/e 



% 



/;/. 



16 



^6 



ya 



% 



F 



^8 



3/4. 



y/6 



'A 



^ye 



CLEAf^ANCE 



H = K 



ya 



iiy 



'/& 



'V/e. 



Spacing 



L 



ly^ 



/% 



jya. 



M 



V8 



lya 



ffiVET Dimensions 



Diam. 



V^ 



V8 



D 



ly^ 



/yi6 



7^ 



^//a 



Ye 



"/l6 



F 



1^/6 



/ye 



r/zc 



"/a 



Vl6 



'/z 



Cleai^ance 



//=A' 



Ve 



/^6 



Spacing 



L 



1/4- 



~^Ve 



M 



IW 



/ya 



/re 




T- Bars Cambria 


Flange 


Stem 1 


Wdf. 


A 


Max. 
Fti^. 


Dpth 


B 


Max. 


5 


zh 


^ 


4 


24 


/ 


A-yz 


ly^ 


- 


zyz 


2 


- 


4 


2 


Vs 


3 


M 


^8 


5^ 


/4 


■ 


zyz 


/^ 


^ 


3 


/^ 


Vz 


2^ 


/A 


" 


Z\ 


lye 


■• 


z 


/>h 


% 


Z'^ 


M 


• 


Ih 


1 


" 


zy^ 


/ys 


" 


l^s 


^ 


'/z 


2 


1 


" 


ly^ 


'Mg 


" 


4 


ya 


y^ 


1^6 


ya 


1 


ix 


M 


M 


lys 


% 


■' 


1^ 


11 


II 


iJfs 


' 


ye 


//s 


" 


n 


1 


- 


■ 


1 


m . 


" 









Hi VET Dimensions 




<^ 



F 

1 



147 



Table No. 14 









Jaw Clutch Couplings - 


J 












Jaw 


Clutch Couplings -2 






/■M 


*H 


t— "" 


1-* 

T" 


t-/f 




■ X-^>N 






M 


# ^M^ 


H 


^> , 






— 


i 


- H 


- ] 


A / \ ^ 




iy///M. 


i^ . 








ILj^ 




v/////////m. 


r.i'Y \ ^^1$«^ 


t 


1 n 










f^ \ -n.^^, it^.. 1 


' 1 ' /: ' c---./.— u--.. 1 


^ ' 1 


A 1 


^1 




2i: 


- 


: 


'm'-- 


-JC- 


rT 




\r^ 


— f- 


1 ,„f.^, ..^y 1 

n 1 ' 1 


\M 


_r — 




V 




/ 




— ^ 




L 

1 JJ 


> 


1 

1 
1 


1 

1, 


^^-TT -Ai 


1 


<-6 ^ 


-\,^ — > 


L 




V + -IS 


r 




\j '1 1 


v^ 




1 

1 




I 

* 


l> 


*-\ 




'^/d^^fMii^-^ 


1 


. ^M^ 


w^ ■• 


\ 


< — 


F ^• 


-F 










7/y^/7Z. ., 5^.^^' 






< /_ — 








?^h , 








*l Joue) « Laughlin Co. 


r C 


n *= H C »1 Unk BtU Co. \ 


D 


A 


B 


c 


E 


F 


G 


H 


J 


K 


L 


M 


/v 




D 


A 


B 


C 


E 


F 


6 


H 


J 


K 


L 


M 


A' 





p 






No.afJoHS 
£<f. Spir. 


li 


S 


H 


z 


3 


H 


he 


3 
•*- 


i 


3 

a 


-^i 


^i 


3 

e 




% 


3 


Zi 


3i 


1^ 


^ 


li 


1 


f 


Z 






/ 
4- 


H 


^% 






z 


Z 


/I 


s^ 


^n 


^i 


H 


H 


Z 


/ 


f 


r 

/6 


Si 


H 


k 




Ih 


H 


2^ 


3k 


/% 


% 


Zi 


1 


f 


Z 






k 


'H- 


zi 






■■ 


II 


a 


H 


H 


H 


^ 


s 


zi 


/ 


* 


i 


H 


^i 


^ 




Ik 


-f 


H 


H 


l-i 


r 
a 


^i 


/^ 


4r 


2i 






3 

e 


4i 


2| 








^ 


ai 


H 


^h 


3 


H 


H 


^h 


/# 


6 


h 


loi 


6i 


9 
16 




lik 


H 


3i 


H 


1^ 
la 


'S 


Zi 


li 


1: 


Zi 






^ 


s 


^^ 






« 


m 


^i 


8 


^i 


H 


5 


H 


2- 


li 


1 


a 


Hi 


6i 


f 




lH 


s 


^ 


^i 


lii 


/ 


^i 


li 


% 


3 






i- 


si 


si 






•• 


u 


sk 


H 


6.i 


H 


H 


6i 


3i 


/i 


li 


Ik 


i4 


H 


// 
16 




^i 


si 


^ 


4i 


/^ 


/ 


3i 


li 


# 


3i 






7e 


si 


si: 






II 


-4- 


3 


H 


6i 


4- 


6 


7i 


H 


li 


li 


i 


/^ 


a 


4- 




Ek 


6 


H 


sk 


/^ 


Ilk 


H 


li 


/3 
/6 


3i 


1 


z% 


# 


si 


3 






■■ 


H 


3i 


loi 


7;S 


^i 


ei 


di 


^li 


li 


li 


/3 
I& 


iH 


^i 


13. 
/6 




^h 


Si 


H 


si 


li 


Ik 


4i 


li 


/S 
/6 


^ 


Ik 


3k 


/6 


H 


3i 






4- 


" 


H 


II 


^i 


^i 


7 


8i 


^% 


li 


li 


7 

a 


/6i 


9i 


7 

a 




^fi 


7 


si 


6 


Z 


li 


H 


li 


#. 


^ 


li 


3k 


i: 


7 


3i 






■• 


■• 


H 


Hi 


6h 


5 


H 


3i 


H 


li 


li 


15 
16 


I7i 


si 


% 




3k 


8 


ei 


7k 


^i 


Ik 


Si 


li 


AT 
/6 


Si 


li 


3^e 


i 


6 


H 






" 


1* 


4- 


i^i 


9 


-^1 


6 


10 


^i 


2 


/i 


1 


I8i 


loi 


1 




^I 


9 


7 


7i 


^1 


1^ 


H 


li 


Ik 


Si 


1^ 


4| 


1 


9 


H 






m 


" 


H 


i^i 


^h 


H 


&i 


'oi 


^^ 


^i 


/i 


Ik 


I9i 


Hi 


Ik 




^k 


10 


7i 


s% 


zi 


1^ 


^i 


z 


/i 


^i 


2 


sk 


li 


lOi 


ei 






" 


H 


^i 


14- 


loi 


G 


S 


Hi 


sk 


Bi 


z 


li 


a4 


Hi 


li 




4^1 


II 


Si 


loi 


2J 


/# 


7i 


zi 


Ik 


7 


Zi 


sk 


li 


Hi 


7§ 






■■ 


■• 


5 


I5i 


Hi 


H 


10 


|^^ 


H 


Bi 


zi 


li: 


23 


/3 


li: 




6k 


IZ 


6i 


//^ 


^a 


li 


ai 


^i 


Ik 


7i 


Zi 


^i 


li 


/^i 


a 






" 


•• 


6 


isi 


/3i 


a 


IZ 


IS 


^4 


3 


H 


li 


^/i 


l^i 


/i 




^.i 


13 


H 


/2i 


<e.^ 


/i 


ei 


^i 


Ik 


a 


Zi 


6k 


li 


/3 


^i 






■■ 


" 



Table No. 15 



148 




o. 



to 



^"^ 



o 





^ 


^ 3 


^ 


5i "0 


« 




•^^ 


■V „• 


10 




.^ 


1 i^^ 


> 
^ 


1^ 



^ 



(0 



o. 



>^ 



^ 



^ 



k 



kl 



•^ 



O 



QQ 






l^ry, 



^liO^iS 



~>lt 



-to 



cvj 



~l<o 



-li-"^ 



(Dl:^ 






MM 



-|^^ 



cnCS 



-llVJ 






CVsJ 



l^ivo 



1^ 






-IN 



"sieo 



HM 



::l5e 
-loo 



H<io 



JS» 



Id((0 



lOJCQ 






Noo 



''M'O 



^liS 



N<o 






-~1M 



15- 



-^^H^ 



HtvJ 



lO 



N«0 
-Itvj 

Moo 



•^liS 



f^lao 



^5$ 






-1^ 



Mi* 



folrj- 






r\ 



fr> 



-IM 



N5« 



W^loo'olco 












yi« 



NOQ 



•^loo 









lis 



H^ 



SM 



l^ 



loioo 

10 



lO|(o 






►Oloo 



il^fi 






N^) 



:lvo 



N^ 



f^ 



00 









^03 






N|VO 



M^ 



►Ol^ 



-Olcj) 
<0 






5!i$ 















Hi 



^93 






-l<o 



'r,\i 









"11 v© 









■o 



■-1CM 



NiS 



h:^ 



'^l^^• 



?\"0 









Jl^ 



Hoo 









^M 
^ 



CM 









.l«o 



-loo 



Mi 






Hi 
00 



-I'M 
4 






•li 






"»1«0 



VO 






N^ 



t-loo 






Hi 



-IN 



^Hi? 



N»|i 

00 









•li 






M 



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-i<\J 



^|VB 



N|ao 



0^ 






loliS 



'^l!^ 












H<\j 






"^00 



-IM 






Hi 



Hm 



^^ 






c\j 



"i|oo 



■^loO 






-^ 






cnl*o 



^ 



Moo 






mi« 



(nl« 



^\^ 



Si 



<^ 



"Olao 



'li 



^ 



;^ 



00 






'^^ 



"^OO 



|<»|<D 



-^li 



^\Vi 









00 






(nljo 



-1^ 



00 



N«o 



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Hi 






00 



•li 
Hi 



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^4 









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^ 



0^ 






^i? 



-1:^ 












M<C 






Qo 



10 






00 



-li 
Hi 



•IM 



-1«0 

7ii 



•^i 



-loo 



w^ 



-li 
00 



"il<D 



-i;S 



-li 

CO 






-KVi 



-^li 



Moo 



00 

-jto 

wiloo 



■^1^ 



T<\^ 



'^1!$ 



-I'l- 



-100 



<>) 









o^ 



CM 



N 






Moo 



>0(ao 



00 

-li 



'^100 

r^joo 



N|00 



«0|V 



-^ 



Oi 



-^i 



-I'M 



51^ 



-1^ 



-IW 



i^lOO 



-^ti 
0^ 



-|<VJ 

Si 






^ 

^ 



!^ 






5I» 



149 



Table No. 16 





Compression Couf 





NGS 










\^T=H >l 


Soli 


D 


Journal 


Boxes 












T 






r 














1 




r4-+^ 


1 


^T 






\ Vh\\ 


=t~ 


-//->! 




< 5 7 


\ 




. 


k^ 


^>w^ \ 






3 Ribs 


fa 


/ff 


then 


4- 


n 


i 


V y 


r 






1 1 




1 ' 


1 








I^^Base^o/^ ^^Xy^>^ 


^ V 1 




^ 1 /- 


olt 


1 1 




J_^_l 


J...., 


«-A 


\ 




^ 


^C 


M n 


\ 


^^Lr^W 1 


/•I'l 




. 1 1 




~p 


.L 


4> 




- U 




1 


f'7/\ 


U 1 J 




l/^^^ 


is^ / 




*0 '=16 










.^-- 


'/? 


A^\ 






1 ^ 


\^ J=B 


<-// 


1 


-> 


U [J 








V 


^ 


y 






< 


-6-* 


Diam. 




— / 


■y-j 




-^ L. < 






1 


B 


1 


















1 
1 
1 


1 
1 
1 






1 

1 
1 


I 

1 
1 






s 






i 


1 
1 

1 




_ 


D 


>} 


B 


C 


E 


F 


G 


H 


J 


K 


L 


1' 


~~ 






h 


^. / 


^^ 


li 


3 
4- 


3 

16 


s 

16 


H 


Hi 


fe 


I 

16 


4-i 




H^ 






^ 


-F — 


1 




t 






u 


1 


^ -■ .1 


i^G li 


^^ 


1% 


fe 


1 


f 


2| 


<2t 


8 


1 
16 


3^ 


< C7 > 






A - 


1 








l^e li 


^^ 




7 
3 


1 
4- 


3 

e 


3 


^1 


1 
16 


1 

a 


6 





A 


B 


C 


E 


F 


6 


// 


J 


/f 


L 


Af 


N 





P 


9 


/? 


«s 


u 


K 


/I li 


H 


2/^ 


1 


S 


7 

16 


^i 


3k 


J-. 
16 


1 
e 


6i 


IS 
16 


H 


1 


li 


li 


1 


2 


li 


3i 


f 


^ 




li 


i: 


3. 

8 


i 




li 


li 


3 
« 


Its 2 


H 


^k 


li 


3 
8 


1 
Z 


H 


2| 


1 
& 


1 
a 


H 


l^e 


&i 


li 


2i 


//i 


a 
/6 


2i 


7i 


^ 


7 
8 


9. 
16 




li 


7 
/6 


a 


3 
4- 


f 


/I 


/# 




<2^ ^^ 


^f. 


3k 


li 


7 

/6 


9. 
/6 


^fs 


^1 


9 

16 


-k 


5| 


//i 


6| 


li 


^i 


1^6 


f 


J 


H 


^i 


7 
'8 


9 
/6 




/* 


1 


3 


IS 
16 


7 


/f 


2i 


-k 


2^ Zi 


G^e 


3^ 


li 


7 
16 


9 
16 


^i 


^f 


9 
16 


a 


H 


1^6 


ri 


Ik 


2i 


1^6 


f 


3i 


zi 


Si 


li 


3 
A- 




£ 


s 
-a 


i 


Ik 


i 


2i 


2/^ 


s 
'a 


2^ 2i 


7 


4.3 


/.i 


1 
2 


§ 


^J 


H 


5 

a 


1 
a 


loi 


lis. 

1/6 


&i 


Z 


3k 


^i 


i 


■4- 


H 


6 


li 


5 
4- 




Zi 


f 


r 

6 


li 


2 


2| 


3i 


a 


^f. 3 


7-k 


^9 


li 


9 

16 


II 

le 


H 


3i 


i 


3. 
16 


Ilk 


^^e 


9 


^i 


3k 


^i 


3 
4- 


H 


3i 


^i 


li 


3 
4- 




^i 


1^ 


7 

8 


li 


2 


J 


3i 


s 

8 


3^ Ji 


H 


^I 


i§ 


e 


3 


6i 


^k 


i 


3 
/6 


izi 


2i 


5i 


zi 


3f. 


2| 


7 

a 


5 


3^6 


7 


li 


3 

4- 




^i 


3 

4- 


/ 


li 


9 

/6 


-?i 


3'i 


4 


3i 5i 


Si 


5^s 


lik 


s 

8 


3 
4- 


e§ 


^k 


3 
4- 


h 


l^k 


p IL 


/^l 


2| 


H 


3k 


7 
a 


H 


H 


H 


li 


7 

a 




3 


3 
4 


/ 


li 


/f 


-^i 


4| 


3 


5% J| 


si 


^a 


1^ 


/6 


16 


rrs 


H 


7. 

8 


3 

/6 


l^k 


'^ /6 


// 


3 


4§ 


3fe 


IS 
16 


6 


4i 


Si 


li 


i 




^i 


3 


li 


li 


9- 
/6 


H 


^1 


3 


Jf 4 


H 


&re 


li 


3. 


7 

8 


7i 


^f 


7 
6 


1 
■=?■ 


isi 


3k 


/■/i 


3i 


5 


^% 


1 


6i 


^1 


s§ 


li 


^ 


pi. 


3i 


7 
a 


li 


/,4 


J- 
6 


4i 


Sk 


3 
4- 


4h ^4 


lok 


Gi 


a 


3 
4- 


7 
8 


7M 


4f 


7 

8 


/ 
4- 


1676 


3^6 


IZ 


3i 


5h 


•^J6 


1 


7 


Si 


Si 


/i 


7 

8 


3 


3i 


i 


li 


/J 


J- 


4| 


^/l 


4- 


-^i 4i 


II 


Gi 


2i 


13_ 
16 


16 


H 


^i 


1 


1 
4- 


I7T6 


3ik 


tzi 


H 




^i 


li 


7i 


S§ 


H 


li 


7 
a 


H 


4- 


i 


li 


/,-§ 


1 


■5^ 


>^;f 


3 


-^t 5 


IS 


H 


^i 


/S 
/6 


Im 


H 


^a 


1 


^ 


19 


3^ 


I2i 


4- 


6 


H 


li 


8 


6 


10 


1^ 


7 

8 


3i 


4.x 
^4- 


1 


7i- 


/^ 


^^ 


^f 


6f 


^ 



Table No. 17 



150 























r\ 


L J 


, f 


-1,1 


R 


IGID 


Pillow 


Blocks 




















Plain 
0. . . 


1 


V i '1 r Y T 








<■■/=' > 


. 


OMAK 1 

Collars 

/5c, >^ 


, /v|\-W/lk-/? 


\ 


^ 


_ t 


P 1 /I 




. ^ 


'y\ 


'^/^e^^^ 


T 


C-H-) 


if -^ 




'-f 


■ 


m 










i 


1 


1// 


Nl 


1 


^-t/- 


-^ i 




Hfr 


- 


i. 


1 //^-- 


^^ 1 


Vii i 


l*-JV-»| 






a 


>\ 


4^4- 












+ ■ + 


1 


:'"TLp^ 


- \r 


i 


1] 
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- 






r- 




-H-i- 








( 


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/ 




1 


M 


1 \ i^ 


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f b-haseboir « 




1 


1 


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. 


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c/ 


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1 


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t 






t — '^ 

— /C — 


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4 


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t 


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r 


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ya 


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m 


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eye. 


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1/3 


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6 


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3 


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Z/e 


2^ 


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3% 


1/^ 


m 


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z-% 


6 


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S 


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ra 1 


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^ 



151 



Table No. 18 











/ 


'X 


.,xV^ 




Angle 


F 


'jLLow Blocks 

Cap 


Bolt 


-a- 


V 












Safety Shaft 


C( 


DL 


LAR 


s 

c 


^^>^X-^^^^ %X ifP^ — ^1^ 


t ^ 


J -r-TS. 


\ Xr'2$^-c^^^w A- ,J--^'. ' ■ =^^j=^ 


<' II 


A / ,.^^^'rv ^k 




X /^^^^^y 


(^^t^^r 


C 1 










-&WH D- 

3^ i. 


y^^^ 


f 


\/\\ 


1 / 


IW 


- 






k-/VH^Ak- 








\ ^^ 




Vllt~ 




ix:?! 


. 




r~ 


s 


1 


(1 


D\ 




\^: 


y 


>^,A^ 


%/0\) a-Base Bolt 


=_ 




1 










1 ^ 


^>r-» 




--r ^^ 


^ 




V/ ,>/ 


L ^ 


1 


n J I r- 


-~-\ 


^^ 


^ ' u 




1 
1 


1 \ 


/T — r 


1 - 
1 


F 




ii 


1 1 11 


h ■ 

I 1 

I I 






1 




yy 


' V 




D 


A 


8 


C 


£ 


F 


G 


H 


J 


K 








n w 






\ 




< 

s 


— P 


R -X 


> 




3i 


1/6 


z 


li 


i 


1 
/f, 


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s. 

6 


-•^ ^ 


^^0-. ' 








i ^ 2 -H 


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Ih 


H 


z 


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li 


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li 


3 
a 


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a 


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c 


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G 


H 


u 


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Z. 


M 


N 





p 


Q 


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5 


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1 

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1 
z 


3 

4- 


if 


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i- 


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1 
a 


ih 


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1- 


i 


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I& 


li 


3 


H 


Ik 


3 


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1 
4- 


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1 


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li-s 


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3 


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6 


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4- 


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16 


32. 


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3. 


3 
32. 


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6i 


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lo-k 


3 


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3 

7e 


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7% 


3h 


sk 


H 


fs 


S 
3Z 


P-Z-2-J. 




-?-^ 


I5i 


7 


6 


^1 


li 


s 


3 

a 


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7 


li 


i 


li 


^i 


8 


l^i 


3 


JZ 


7 
8 


/ 


6 


3 

7e 


3 

-4- 


4.4 


7i 


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H 


3 


s 
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J. 

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Z^^'i 




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J7i 


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6 


3 

8 


5 


H 


li 


f 


2i 


6 


S 


14- 


H 


13k 


't 


/ 


6i 


i: 


7 

a 


4k 


si 


ek 


H 


3h 


IL 
32. 


3 

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o9 Z-Z 


1 1 
I4- 


4ii 


I8i 


<si 


7i- 


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li 


H 


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8 


H 


si 


/f 


f 


Zi 


H 


10 


15 


^i 


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li 


1% 


7 


1 

4- 


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9i 


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7 


3i: 


i 


^ 


p// z-1 
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li 



Table No. 19 



152 



Pulley Proportions 




Spur Gear Proportio ns 

Pt 




A- /Wo. of Arms 
p- Diam. Pitch 



B-£ C 



- ±i +„ F Lj- D-l-aF . r If - c/ 

•?• ^^ 



Assufve D- p- cf-A 
J 

F- See ya/ues behyv ^'^ n^^ 



/r=^ 



L=fF toF M =/^ (Sin^.Be/fj M=?f§^ (Ooub. Be ft) 

N = ^ 0=^M i-o ^M P=% 9=^d ^=^ 
S 3 4 Z ^ /6 ^ 

e a 



L^F-/-^ M=/iIE^ A=M o=^M fo^Af 

^° / Ap Z 3 ^ 



^'i 



z a 



/= j/r 



P 



F 



/i 



7i 



li 



6-^ 



/^ 
/^-i. 



H 



Zi 



^i 



3 \3i 



i"\ 



\2i 



S 



fi 



8 



/i 



153 



Table No. 20 



CO 

•J 

w 

H 
<d 

o 

h 

DC 

O 
i-i 

m 



Mfi, 

So 



ooooo ooooooooooo 

lOTfir-tiO-^O^t^CMCOCOr^COCMiOOOO 

ioooG0OO(M ooooooooooo 

(M^OOOCqiMt^OlCOOCD^^OOi'^t^l-^ 



lO lO O CN 
CO lO (M CO 
I III 
lO -^ O kO CO lO 
lO 00 lO T— I C^ lO 



lO t^ O 

iO "^ ^H vo lO 
CO I I • I 
t^ O CO 1^ lO 
O ^ lO lO 



m 

CO 

(M 

CO 



u 

^" 

u 

o 



03 

w 

o 

s 
s 

1^ ^ 



o 

o 



S-i 

o 



CD 

' So 

03 



s^l^ 3 



«^ffl 



;e 53^ o 03 
CQOOOH 



CD 

c 
o 

CO 



:s S 



o 

02 



-^3 






CD 

Oc5as 



^ i 

o ■ 
to ■ 
c3 



<D 

c 
o 

CO 

— rt C ti o3 
^g 03 o3 ^ ^f-i 



o 
m O O 

Pl4 



<d" 


CO 




O 


a 


C 


Tl 




+3 




c 




<:» 





m 


r^ 8 




s 






^^ . -4:5 




g 


.-H CO '^ 

CO 




cd 


, • ID cn 


_ S 


"3 


f-i • 


rcoa 

e 

roleu 


w 

g 


at6( 
tmos 
es fr 


03 ^ += 




ij o3 -s 


_C O CD 




.a " CO 


OOPh 




<: < 



03 

C-l o 

CO CO 
03 03 









Oh . 
3 



CD ■* ^ in 00 (M (33 
O rfi lO o o o 
O IM CO CO CO (M CO 



lO'X'— '■— iiOOOi— It— iCOCOCi^OOO 

c-i^(M'-ic:iinoO'-icJ3ooi^t^ooco-* 

COCOCOCOCD(N(M^xf<-*l-^CO(MC^(N 



ooi'-HC-icooco9o-*LOcoocooOrt'*cO'*ino3-*<N 
i-^^coiniOiOiovoinioioiM-^-^t-^oooococo-^-^-^ 



looii— iiocoiomcocovnc^o^ooict^'— I 
TticD^T-iir^cocMininco-^mcNcocMcoio 





















i4 




















1) 




















^ 




















a 


^ 






er. Sheet 
Wire 
Cast 

Cast 
Wrought 




(M 
(N --1 








>, 




iuminum 

ntimony 

ismuth 

rass. Sheet 
" Wire 
" Cast 


CD 




ury at 3 
at 2 
num 






Sheet 
Cast 


V4 

Q 

CO 

•0 





P 


p 


o3 
<D 




CD 


0) 










<<cq:q 


PQ 


^^ ^^ l-H H-t 


hJ S Ph OJCO tS! 














Table No 


21 









CO 

o3 

ckPh 



o 



o 

<:pqooHWWWS 



3 

CI 



S '3 



(3 
o3 

O - 

-a 





CD 


White 
White 





Mapl 
Oak, 
Pine, 


- 



CD 

o 
Ph >.^<d 



154 



INDEX 



155 



Addendum, tooth . 

A. L. A. ^I. bolts and nuts 

Alterations, blue prints 

" lettering 
Anchor bolts . 
Angle gears . 

" valve . 
Angles, specifj-ing 

■■ structural 
Architectural lettering 
Arrows . 
Artists' perspective 

A. S. M. E. Stand, screws 
Assembly drawings 
Axometric 

cube . 
" exercises 

Ball handles 

B. & S. tapers 
Batten plate . 
Belting 
Bend, pipe 
Bevel gears . 
Bevels, structural . 
Bill of material 
Birm. wire gage 
Black printing 
Blue printing 
Blueprints, alterations 
Bolt, A. L. A. M. . 

" eye . 

" general . 

" manuf. stand 

" U. S. stand. . 



SEcnox 
134 
Tab. 4 
89 
317 
107 
149 
130 
57,68 
169, 175, Tab. 14 
296, 301 
47 
6, 210, 270 
117, Tab. 5 
21 
10, 230-257 
233 
258 

Tab. 9 

132, Tab. 13 

175 

78 

130 

142 

159 

84 

133 

90 

86 

89 

Tab. 4 

Tab. 10 

106 

110 

109, 110, Tab. 1 



Bond paper . 
Books on lettering . 

■" toothed gears 
Broken ends . 
Building plan 
Button head . 

Cabinet projection 

" exercises 
Cap screws 
Castings 
Cast washers 
Center Unes . 
Chain 
Channel 

Checking drawings 
Check valve . 
Chord . . 
Circle, division of . 
Circular mU . 
Circular pitch 
Clearance, rivet 

tooth . 
Cle^-is 
Chp angle 
Clutch coupling 
Coach screw . 
Collar screw . 
Compression coupling 
Coping, structural . 
Cotter . 

" pin . 
Countersxmk head . 
Coupling, pipe 
shaft 



SECnON 

86 

318 

150 

26 

176 

114, 121 

■ 8, 264-266, 274 

267 

112-114, Tabs. 2, 3 

41 

Tab. 10 

36 

78, 252 

169, 175 

206 

130 

175 

198, 199 

78 

134-137 

165, 174. Tab. 14 

134, 137 

175 

175 

Tab. 15 

119 

115. Tab. 4 

Tab. 17 

175 

126, 127, Tab. 10 
175 
114, 121 
130 
Tabs. 15, 16, 17 



156 

Cover plate . 
Crimped angle, struct. 
Cross hatching 
Cross, pipe 
Cross section paper 
Cross valve . 
Cycloidal teeth 

Decimal equivalents 

Dedendum, tooth . 

Detail drawing 

Diametral pitch 

Dimensioning 

Dimension figures . 
lines . 
" location 

" selection 

Dotted lines . 

DrUled holes . 

Elbow, pipe . 

" axometric of 
Electrical symbols 
Elevation 
Ellipse isometric 

" sketching 
Exercises 
Extension lines 
Eye bar 
" bolt 

Face of tooth 
Field rivets . 
Filler, structural 
Fillets on castings 
Fillet, tooth . 
Fillister head 
Finish marks 
Flange coupling 
Flange, structural 
Flank of tooth 



207, 229, 258; 



44, 



SECTION 
175 

175 
33,35 
130 
202 
130 
138 

Tab. 1 

134, 137 

21 

135 

37-72, 173 

58-64 

46, 53, 173 

72 

38 

29 

78 

130 
251 
208 

18 

260 

200 

, 263, 267 

48 
175 
Tab. 10 

134 

175 

171, 175 

41 
134 
113 

41 

Tab. 16 

175 

134 



Flats . 
Forging 
Foundry plan 

Gage, machine screw 
" steel wire 
" twist driU . 
" U. S. sheet metal 
" wood screw . 

Gage lines 

Gages 

Gate valve 

Gear books . 

Gearing, toothed . 

Gear teeth 

Gib head key 

Globe valve . 

Gusset plates 

Hand wheels . 
Handles, machine . 
Hanger, shaft 
Hatching, cross 
Hehx angle . 
Hitch angle, struct. 
Horizon line . 
Horizontal projection 
H section 

I beam 

Involute teeth 
Isometric drawing . 

" exercises . 

" paper 

" pipe drawing 

" projection 

Jarno taper 

Jaw clutch coupling 

Jom-nal box 

Keys 



SECTION 

175 

39 

, 176 

Tab. 5 
133, Tab. 5 
Tab. 5 
78, 133 
Tab. 5 
164, 175, Tab. 14 
133 
130 
150 
134-150, Tab. 20 
134-139 
122, Tab. 6 
130 
170, 175 

Tab. 8 

Tabs. 8, 9 

78 

33 

146 

175 

218 

18 

175 

169, 175 
138 
-262, 272 
263 
262 
131 
11 

132 
Tab. 15 
Tab. 17 

122, Tabs. 1, 6 



12, 259- 



Keys Whitney or Woodruff 
Knobs, machine 
Knurled head 

Lacing 
Lag screw 
Lateral pin 
Lattice bars . 
Laying out floor 
Lead of a screw thread 
Lengths, estimating 
Lettering . 

Alphabets 

Alterations 

Books on 

Mechanical 

Photo reproduction 

Practice work . 

Principles 

Titles . 
Linear perspective . 
Line shading 
Lines of a drawing 

Center lines 

Dimension lines 

Dotted lines 

Extension Hnes 

Shade lines 
Lug angle 

Machine handles . 

" screws 
Map titles 
Materials, weight of 
Mitre gears . 
Model drawing 
Morse tapers 

Nominal sizes 
Normal pitch 
Notes appended to drawings 



SECTION 

124, Tab. 1 

. Tab. 7 

111 

175 
119 

175 

. 172, 175 

152 

103 

180 

284 

. 296-297 

317 

318 

285 

. 315, 316 

. 303-314 

. 288-295 

. 298-302 

5, 209, 217,269 

. 277-283 

80-81 

36, 81 

44, 81, 173 

29, 81 

48, 81 

. 275, 276 

175 

. Tab. 9 

78, 117, Tab. 5 

300 

. Tab. 21 

149 

. 222-227 

132, Tab. 13 

78 

145 

74 



Nuts, standard 

Obhque projection . 
OldEngHsh . 
Open holes, struct. 
Orthographic projection 
Outlet, pipe fitting 

Panel, struct. 
" point 

Perspective, artists' 
" Unear 

" principles 

Picture plane 

Pillow blocks 

Pin plate 

Pipe drawing 

Pipe, standard 

Pipe fittings . 

Pitch hne of gears 

Pitch of gear teeth 

Pitch of rivets 

Pitch of roof . 

Pitch of thread 

Plan view 

Plotting curves 

Plug, pipe fitting 

Positive prints 

Projection, cabinet 

" horizontal 
" isometric 
" obhque 
" orthographic 
" profile . 
" sketches 
" third angle 
" vertical 

Pulleys 

Purlin, struct. 

Rack 



157 

SECTION 

109, 110, Tab. 1 

7,273 

297 

161, 175 

9 

130 

175 

175 

6, 210, 270 

5, 209, 269 

. 211-221 

5 

78, Tabs. 18-19 
175 
131 

78, 129, Tab. 11 

130, Tab. 12 

134 

134^137, 145 

. 167, 175 

175 

102 

18 

. 201, 241 

130 

90 

8, 264^266, 274 

18 

11 

7, 273 

9, 271 

18 

202-205, 207 

15 

18 

41, 78, Tab. 20 

175 

141 



158 

Railing fittings 

Reducing coupling 

Retm-n bend, pipe 

Riser, pipe 

Rivets 

Rivet clearances 

" dimensions 

" signs . 

" spacing 
Rod and bar stock 
Rolled sections 
Rope 

Rounded corners 
Run, pipe fitting 



Scales for drawings 
Screw, button head 

" cap . 

" coach 

" coUar 

" countersunk 

" drawing of . 

" fillister head 

" headless 

" hexagon head 

" knurled head 

" lag . 

" lead . 

" mac ne 

" set . 

" square head 

" wood 
Screw gage . 
Screw threads, Acme 

" buttress 

" " conventional 

" double . 

" " International 

" " knuckle 



112, 



114, 



SECTION 








. Tab. 12 


Screw threads left hand 


130 


" " multiple . 


130 


" " pipe 


131 


" single 


121 


" " sketching 


. Tab. 14 


" " square 


. Tab. 14 


" U. S. standard 


162 


" Vee 


. Tab. 14 


" " Whitworth 


78 


Secondary members, struct. 


169 


Section Iming 


. 78, 252 


Section symbols 




41 


Sections 




130 


Separator 
Set screw 




22, 23, 155 


Shade lines 




114, Tab. 3 


Shaft collars 




Tab. 2, 3 


Shafting, size of 




119 


Sheared plate 




115, Tab. 4 


Sheaves . 




114, Tab. 3 


Sheet metal gage 




. 101-104 


Shop rivets . 




113, Tab. 3 


Sketching of angles 




Tab. 2 




' axometric 


112, Tab. 2 




' of circles 


111 




' of cube . 


119 




' of eUipses 


98 




' exercises 


171, Tab. 5 




' of hexagons . 


116, Tab. 2 




' of irregular forms 


112, Tab. 2 




' Isometric 


120, Tab. 5 




' Projection 


Tab. 5 




' of threads 


98 




' of triangles . 


95, 96 


Sole plate 


101 


Specifications on drawings 


103 


Spiral gears . 


93 


SpHce plate . 


99 


SpHt pin 





SECTION 

104 

103 

100, Tab. 11 

102 

244 

97 

92, Tab. 1 

91 

. 94 

175 

33, 35 

34 

30 

175 

116, Tab. 2 

. 275, 276 

Tabs. 18-19 

78, Tab. 16 

175 

78 

78, 133 

175 

199 



181 



207, 



229, 



258 



198, 

230-257 
191 
224 
200 

263, 267 
189 

241, 260 
262 
202 
244 
187 
175 
73-77 
144 
175 
127, Tab. 10 



Spring cotter 
Springs 
Sprockets 
Spur gears 

" " axometric of 
Stay plate 
Straight coupling . 
Structural drawing 
Stubs' iron wire gage 
Stud bolt 
Sub titles 

Tap bolt 

Tapers . 

Tapped holes 

Tbar . 

Tslot . 

Tee, pipe fitting 

Templets 

Third angle projection 

Through bolt 

Tie plate 

Titles . 

Tooth angle 

Tooth proportions 

Tracing cloth 

Truss 

Tubing 

Twist drill gage 



SECTION 

127, Tab. 10 

128 

78 

140, Tab. 20 

257 

175 

130 

. 151-175 

133 

106, Tab. 4 

73 

106 

78, 132, Tab. 13 

105, Tab. 4 

169, 175 

Tab. 10 

130 

152 

15 

106 

175 

298-302 

146 

137 

86 

175 

78 

133, Tab. 5 



Union, pipe . 

Universal mill plate 

Upset rods 

U. S. standard bolts 

U. S. standard gage for plate 

Valve, pipe . 
Vanishing points 
Velocity ratio 
^'erticaJ projection 
Views, selection of . 

Wall brackets 
Washers 
Web plate 
Weight of materials 
\Miite lines, blue prints 
Whitney keys 
Wire gage 
Wood screws 
Working drawings . 
Working lines 
Worm gearing 
Wrought iron pipe . 

Y branch, pipe fitting 

Zbar . . 



159 

SECTION 
130 

175 

175 

109, 110, Tab. 1 

133 

130 

217 

149 

18 

24 

78 
118, Tabs. 9, 10 
. 171, 175 
. Tab. 21 
89 
124, Tab. 1 
133 
78, 120 
19-85, 151-173, 206 
. 158, 175 
143 
129, Tab. 11 

130 

. 169, 175 



SEP 17 1912 



